How Mass Media Influences U.S. Political Polarization— A Comparison Study of CNN and Fox News

. This paper presents a study on how mass media, specifically CNN and Fox News, have influenced the polarization of American politics concerning environmental policies. The study used a qualitative approach to analyze the content of CNN and Fox News broadcasts related to environmental policies. The results show that CNN and Fox News have significantly contributed to the polarization of American politics, especially on issues related to public policy. While CNN emphasizes the need for environmental protection and regulation, Fox News focuses on the economic consequences of such regulations. These differing views have influenced the political attitudes of viewers and created a divide among the American public on environmental policies.


INTRODUCTION
As a terminology in the field of political science, "political polarization" is currently one of the main concerns also in the field of social and behavioral sciences, as "different societies worldwide seem to have undertaken a path of political conflict recrudescence, intergroup ideological distance, and growing intergroup animus", which has been linked to a range of negative outcomes, such as reduced trust in government, increased political instability, and decreased social cohesion.Over the years, the U.S.A. has concentrated on the factual existence and implicit influence of political polarization that has pervaded.As a sophisticated phenomenon with a wide range of causes and corresponding detrimental consequences, in recent years, the mass media with specific political biases and stances in the United States has been a topic of concern and debate, even if they coverage, critics argue that many of these organizations have a clear political bias that shapes their reporting.
As media has been "a ubiquitous part of modern life" [1] and has inoculated profound influences on many aspects of society, including politics, "many of the current options are extraordinarily social, dramatically increasing people's capacity to form bonds with individuals and groups that would otherwise have been entirely inaccessible" [2].However, concerns have been raised about the role of mass media in contributing to political polarization, which can have detrimental effects on democracy and social cohesion.
This paper aims to use qualitative research methods including textual analysis, discourse analysis, and case yjhchristopher@bfsu.edu.cnstudy on two conventional mainstream media based on their previous and published newsletter on American environmental policies-namely CNN and Fox News, to focus on the mechanism of media in shaping public attitudes towards environmental policies and contribution to political polarization in the US, and to reveal the conceptualization of polarization in politics in the U.S.A.

LITERATURE REVIEW 2.1 Conceptualization of Political Polarization
According to Kubin & von Sikorski [3], the concept of political polarization has been discussed in political science since the 1950s, when scholars began to examine the effects of party systems and electoral behavior on political conflict.Political scientists typically distinguish between two levels of political polarization: elite and mass.Elite polarization focuses on the polarization of the political elites, like party organizers and elected officials.Mass polarization focuses on the polarization of the masses and the public, most often the electorate or the public.
The studies on political polarization have evolved to reflect the changing political and social contexts in the United States.In the 1950s and 1960s, Morgan Kelly [4] claimed that American politics was characterized by a lack of polarization and ideological clarity among both elites and the masses.They suggested that a moderate consensus prevailed in the post-war era and that parties were weak and overlapping in their policy positions.In the 1970s and 1980s, however, other scholars challenged this view and pointed out the increasing ideological divergence and partisan alignment among elites and masses.They attributed this trend to various factors, such as the civil rights movement, the Vietnam War, the rise of new social movements, and the realignment of party coalitions.
In the 1990s and 2000s, scholars further examined the sources and implications of political polarization in the US and other countries.They explored how "institutional factors (e.g.electoral rules, media systems, and campaign finance), psychological factors (e.g.motivated reasoning, social identity, and confirmation bias), and contextual factors (e.g.globalization, immigration, and terrorism)" influenced political polarization among elites and masses [4] [5].They also analyzed how political polarization affected democratic performance and outcomes, such as policy-making, representation, accountability, participation, and trust.
The literature on political polarization has also developed different theoretical frameworks and methodological approaches to understand and measure such phenomenon.Some scholars have adopted a normative perspective and argued that political polarization was either beneficial or detrimental to democracy.Others have adopted a descriptive perspective and focused on explaining how political polarization varied across time, space, and levels of analysis [5].Some scholars have used quantitative methods and relied on survey data, roll-call votes, or text analysis to measure political polarization.Others have used qualitative methods and employed case studies, interviews, or discourse analysis to examine political polarization.

Cause and Effect of Political Polarization
Firstly, social identity has been recognized as a cause of political polarization.Kreiss [6] argued that social identity is a significant factor contributing to political polarization, which is constructed by social groups, particularly journalists in this study, within a specific socioeconomic context.This construction of social identity has important implications for the legitimacy of institutions in the eyes of the public.Journalists are a distinct group of people in society, and their social identity is related to other groups in society.The social identity of journalists is historically specific, contextually relevant, and politically significant, which indicated the significance of social identity to the phenomenon of political polarization (p.27).According to Mason's [7] research, individuals who are highly sorted into partisan groups are more likely to engage in political action, regardless of their policy attitudes.This is especially true when they feel threatened or angry (p.99).
Media consumption is another important factor contributing to party polarization.People today have access to a wide range of news sources, many of which have partisan leanings.This can lead to the formation of so-called "echo chambers", where individuals are exposed only to viewpoints that align with their pre-existing beliefs [8].Mason [9] suggests that when people consume information from mass media, they can gain insight into the extent to which their political behavior is influenced by irrational or unfair factors (p.17).Prior [8] notes that despite the availability of a wide range of news sources, there is still divergence in people's viewpoints.This is because it is difficult to measure the average opinion when it comes to news consumption, which further complicates arguments on this topic (p.285).
Finally, political elites can also contribute to polarization by adopting extreme positions and engaging in divisive rhetoric.According to Noelle-Neumann [9], political elites can contribute to political polarization by adopting extreme positions and engaging in divisive rhetoric.This can create a "spiral of silence," where individuals who disagree with the dominant discourse feel marginalized and are less likely to speak out.Political elites, like the presidents and leaders, may influence the polarization of the electorate (the mass public) by taking more extreme ideological positions and actions, and by deliberately fueling animosity and distrust toward the opposing side [8] [10].They may also use social media to organize offline political activities, disseminate false or disinformation, and increase political polarization among the citizens [8].Political polarization among the electorate may manifest as affective polarization (disliking and avoiding the other side), ideological polarization (adopting more extreme views), or behavioral polarization (engaging in conflict or violence) [29].
Political polarization may have negative consequences for democracy, such as reducing compromise, cooperation, and representation [3].
Regarding the consequences of this political phenomenon, another major effect is that it can lead to gridlock and an inability to make progress on important policy issues.This can lead to a sense of disillusionment and disengagement among citizens, who may feel that their voices are not being heard.
Another consequence is that political polarization can undermine the democratic process itself.When individuals become more ideologically entrenched, they may become less willing to compromise or engage in constructive dialogue with those who hold different viewpoints.This can lead to increased hostility and intolerance, making it more difficult to build consensus and make decisions in the public interest.

Media in Politics
Media can influence political polarization by exposing people to different or similar information and opinions about political issues and actors.Political polarization can also affect media use and preferences by motivating people to seek out or avoid certain sources of information and opinions.The literature on media and political polarization has examined various aspects of this relationship, such as the causes, consequences, and measurement of media exposure and political polarization.According to Humayun [11], media has become an omnipresent aspect of contemporary life and has had a significant impact on various aspects of society, including politics.Sunstein [12] suggests that many current media options are highly social and have the potential to significantly increase people's ability to connect with individuals and groups that were previously inaccessible.This can lead to the formation of strong bonds between people who may not have otherwise connected (p.65).One of the ways that media has been shown to relate to political polarization is through the media's role in shaping public opinion.This effect was particularly strong among individuals who identified as politically engaged.
Selective exposure is also a kind of measure to affect political polarization, whereby individuals seek out news content that reinforces their pre-existing beliefs.
Media fragmentation has also been linked to political polarization.A study by Gentzkow and Shapiro [13] found that the rise of cable news channels and the internet has led to greater fragmentation of the media landscape, with individuals increasingly seeking out news sources that align with their political beliefs.This fragmentation has been linked to greater polarization, as individuals are exposed to fewer diverse viewpoints and are more likely to hold extreme political views.
Another question in the literature is whether media exposure contributes to or reduces political polarization.Some studies have argued that media exposure can increase political polarization by creating "echo chambers" or "filter bubbles" that insulate people from opposing views and reinforce their existing beliefs [14] [15].Other studies have suggested that media exposure can decrease political polarization by exposing people to diverse and balanced perspectives that challenge their prior beliefs and foster mutual understanding [16] [17].The effects of media exposure on political polarization may depend on various factors, such as the type, content, and quality of media sources; the frequency, duration, and intensity of media use; and the individual characteristics, motivations, and preferences of media users.Subsequently, how political polarization influences media use and preferences is also a concentration.Some studies have shown that political polarization can affect media use and preferences by leading people to select or avoid media sources based on their ideological congruence or incongruence [18].Other studies have indicated that political polarization can affect media use and preferences by shaping people's perceptions of media credibility, bias, and trustworthiness.The effects of political polarization on media use and preferences may vary depending on the availability, accessibility, and diversity of media sources; the salience, complexity, and controversy of political issues; and the social norms, expectations, and pressures of media users

Overall Design
Qualitative analysis methods were used to analyze the data collected through coding, which was used to categorize and organize the data [19].Narrative analysis was used to examine how individuals construct stories and how these stories shape their experiences [20].Media texts were analyzed using thematic analysis to spot trends in the way messages are put together and conveyed.The study employs conventional qualitative analysis techniques like thematic analysis, narrative analysis, and coding.
The research was searched from the archive website of CNN and Fox News in a specific period from Dec. 31, 2021 (after Joseph Biden came to power) to the up-to-date deadline of Apr. 1, 2023.After selecting the homogeneous category relating to "environment" from CNN and Fox News and searching under the keywords of the outcome was there emerged 27,201 newsletters on CNN and 25,500 from Fox News.A random selection was conducted: firstly, the newsletters were numbered from 1 to the end according to the time sequence; secondly, use the function of "=RAND ()" in Excel to decide which 50 passages will be selected for each media coverage, thus 100 passages in total, as samples of this research (see Annex 1).This step can ensure equity and randomicity the same number of newsletters would be chosen with validity and credibility.This sample selection will take three decimal places of each value, for example, 0.62514012, and the 625th numbered article from each media outlet of CNN and FOX News will be selected as the sample, as shown in Table 1 and Table 2. States and other countries have long regarded CNN as one of their primary news sources.
CNN is rated as having a center-left bias in the Ad Fontes Media media bias chart, which assesses news organizations based on their bias and dependability.This indicates that although the news outlet delivers factual information, its reporting can occasionally be swayed by a liberal point of view.CNN is still regarded as having very balanced reporting when compared to other news sources, nevertheless (see Figure 1).Fox News is a conservative news network that covers a variety of news subjects, including politics, business, health, technology, entertainment, and international news, according to Ad Fontes Media.According to Figure 2, Fox News is widely seen as having a significant right-wing slant.This indicates that the news agency offers information from a conservative standpoint and that conservative political ideology may occasionally impact its coverage.By examining media bias in Fox News and CNN, we can learn more about how media bias shapes public perception, how various news networks present political problems, and how media coverage might exacerbate political polarization.In conclusion, choosing these two networks as samples is a legitimate and practical method for researching media bias.

Coding and Thematization
Firstly, the open coding process was conducted by thoroughly reading the 100 passages, with the outcome gathering into the codebook (see Annex 1).Then, the axial coding procedure divided the open codes into three themes: political, environmental, and socio-economic perspectives.By examining and categorizing the codes into the three themes, codes like "Biden", "government", "presidency", "administration", "EPA", "policy", "proposal", "efficiency", "harm", etc. were thematized into "Political" perspective.Such thematization methods were conducted in the codebook.

FINDINGS 4.1 Media Coverage of Environmental Policies: Implications for Political Polarization and the Role of Ideological Leanings
The study found that both CNN and Fox News covered a wide range of environmental policies aimed at tackling climate change and promoting sustainability.These policies included efforts to transition to green energy, implement stricter air pollution controls, regulate waste management, expand national parks, and address issues such as rising sea levels, endangered species protection, and sustainable agriculture.By examining the relationship between media, environmental policies, and political polarization, this study provides insights into the complex dynamics at play.It underscores the importance of media responsibility and the need for a well-informed and engaged citizenry in fostering a more constructive and inclusive political discourse on environmental issues.
The study also found that these ideological tendencies are reflected in the framework, theme selection, and object selection, which may affect readers' interpretation and reinforce existing beliefs, ultimately leading to political polarization

Media Bias in Environmental Coverage: Framing, Topic Selection, and Object Option as Factors of Political Polarization
Firstly, the framing of news stories can be influenced by the ideological leanings of the news outlet.For example, CNN may emphasize the need for immediate and extensive action to address climate change, framing it as a pressing crisis requiring urgent solutions.On the other hand, Fox News may adopt a more skeptical stance towards climate change, focusing on the potential economic impact of environmental regulations.Additionally, the selection of topics covered by each network can reflect their ideological leanings.CNN might prioritize stories that highlight the negative consequences of environmental degradation and emphasize the importance of government intervention and international cooperation.
Meanwhile, Fox News might emphasize individual freedoms, market-based solutions, and the potential economic costs associated with environmental regulations.Furthermore, the choice of objects and topics interviewed on these networks can contribute to biases.CNN's video programs may invite guests who support progressive environmental policies, such as climate scientists and environmental activists.In contrast, Fox News might feature guests who express skepticism towards climate change or advocate for limited government intervention, such as conservative think tank representatives or industry experts.These biases in framing, topic selection, and guest choice can shape viewers' interpretations of environmental policies and reinforce their existing beliefs.Viewers who align with the liberal or progressive spectrum may feel their perspectives are validated by CNN's coverage, while conservative viewers may find their viewpoints affirmed by Fox News.This reinforcement of preexisting beliefs can contribute to political polarization, as viewers become more entrenched in their ideological positions and less receptive to alternative viewpoints.It is important to recognize that media bias is a nuanced and complex issue.Biases can arise from various factors, including the perspectives of journalists, editorial decisions, and the target audience of a particular news outlet.
Additionally, biases can vary within networks, as individual journalists may have their own biases that influence their reporting.To mitigate the potential impact of biases in news coverage, media consumers should actively seek out diverse sources of information and engage in critical analysis.By exposing themselves to a range of perspectives, individuals can develop a more comprehensive understanding of environmental policies and avoid the pitfalls of echo chambers and confirmation bias.

Case Analysis
In the first quarter of 2023, the Environmental Protection Agency of the US government released the latest policy on Electronic Vehicles (EVs), and both CNN and Fox News have covered this policy while simultaneously manifesting their political biases in their passages, which have contributed to macro-political polarization from a micro perspective.
The article "The EPA's Plan to Accelerate the EV Revolution" written by CNN Politics discusses the importance of fuel economy regulations for electric vehicles in reducing greenhouse gas emissions and reaching climate goals.The article implicitly states that it supports the EAP's new policy on EVs, and in terms of emotional color, the words used in the article are focused on straightforwardly presenting information and analysis, without overtly positive or negative connotations.However, some words and phrases such as "critical for achieving climate targets" and "potential to significantly reduce emissions" suggest a positive view of the policy.
Moreover, the article "EPA proposes new tailpipe rules that could push EVs to make up" also written by CNN supports the policy of implementing tougher car pollution standards and promoting electric vehicles to combat climate change, as it emphasizes the benefits of reducing emissions and mentions the support of President Biden and environmental groups.
To judge the emotional color of the words in the article, one can look for language that conveys a positive or negative tone towards the policy or the people involved.For example, positive language used in CNN's passages includes words like "benefit," "progress," and "success," while negative language might include words like "harm," "failure," and "controversy." The article from Fox News titled "EPA administrator claims 'absolutely no punishment' for those who don't buy electric vehicles" suggests a critical stance towards the policy of promoting electric vehicles.The use of words such as "claims" and "punishment" may imply skepticism or doubt about the policy.
Regarding the article "Biden unveils toughest-ever car emissions rules in a bid to force", based on a narrative analysis of the article, it appears that Fox News is critical of the policy announced by President Biden to set the toughest-ever car emissions rules to force electric vehicle purchases.
First, the headline uses the word "force," which has a negative connotation, rather than a more neutral term like "encourage."The article also frames the policy as a "radical" and "expensive" plan that will impact consumers and the auto industry.Additionally, the article includes quotes from Republican lawmakers and industry representatives who criticize the policy.Furthermore, the article includes phrases such as "green agenda" and "climate crusade," which suggest that Fox News views the policy as part of a broader liberal environmental agenda rather than a pragmatic solution to reduce emissions

Media Possess Ideological Bias to Political Polarization
CNN has often been criticized for having a liberal or progressive bias in its coverage.Critics argue that the network tends to favor left-leaning perspectives and often presents news stories and analyses from a liberal standpoint [23].This perception of bias has manifested by viewing CNN as promoting a particular political agenda and catering to a predominantly liberal audience [24], especially distinctive in the verbal usage, emotion, and comments on the environmental policies in this study.This may be seen in the language they employ, the subjects they decide to cover, and the way they frame those subjects in their writings.But it is also crucial to keep in mind that news organizations could exhibit variable degrees of prejudice toward various themes and situations.
On the other hand, Fox News has faced accusations of having a conservative or right-wing bias.Critics argue that the network promotes conservative viewpoints, employs conservative pundits, and frames news stories in a way that supports a conservative narrative [23].Some viewers perceive Fox News as catering to a conservative audience and promoting a conservative political agenda [24], which could also be observed from the environmental policy commentaries selected.Based on the language and tone of these articles, it appears that Fox News is presenting a negative view of the policy and may be reflecting a conservative or right-leaning political bias.
These perceived biases can shape the content and framing of news stories, as well as the selection of topics and objects.The ideological leanings of CNN and Fox News can influence the way information is presented, leading to different interpretations of events and issues.This can contribute to the formation of partisan attitudes and the reinforcement of existing beliefs among viewers [16].
It is important to note that perceptions of bias can vary among different audiences.Individuals with different political affiliations or ideological orientations may interpret the same news coverage differently, perceiving bias in different directions [24].However, the perceived bi-polarized biases on the same environmental policy of CNN and Fox News have contributed to the perception that the media landscape is polarized, with each network serving as a platform for partisan viewpoints [25].

Information Filtering and Selective Exposure Deepen Manifestations of Political Polarization
Individuals tend to seek out and consume news that aligns with their existing beliefs and values, resulting in selective exposure to ideologically compatible sources [18] [26].This filtering process leads to an echo chamber effect, where individuals are predominantly exposed to information that reinforces their preexisting views [12].
CNN and Fox News, as prominent news outlets, employ the environmental policies conducted in this study of Biden's Administration, which cater to their target audiences, thereby contributing to information filtering and selective exposure.Previous research has demonstrated that individuals who identify as liberals are more likely to consume news from CNN, while conservatives are more inclined to turn to Fox News [17].These media outlets strategically frame and emphasize certain political issues, appealing to their respective partisan audiences [16] [26].
Furthermore, technological advancements, such as personalized algorithms and social media platforms, exacerbate the problem of information filtering and selective exposure.These algorithms track users' online behaviors and preferences, curating content that aligns with their past consumption patterns [27].As a result, individuals are often presented with a narrow range of perspectives, reinforcing their existing beliefs and contributing to the echo chamber effect.
The consequences of information filtering and selective exposure are significant for political polarization.Individuals who engage in selective exposure tend to become more entrenched in their ideological positions, as exposure to opposing viewpoints is limited [26] [28].This limited exposure to diverse perspectives can lead to an increase in hostility and a decrease in understanding between partisan groups [17] [25].
To address the challenges posed by information filtering and selective exposure, it is crucial to promote media literacy and encourage individuals to seek out diverse sources of information [7] [26].Additionally, media organizations should strive for balanced and comprehensive reporting, presenting multiple perspectives on political issues [12] [29].By promoting media diversity and providing individuals with the tools to critically evaluate and access a wide range of information, it is possible to mitigate the negative effects of information filtering and selective exposure on political polarization.

Political Polarized Media on Public Attitudes and Behaviors
The media, including CNN and Fox News, play a significant role in shaping public attitudes and behavior regarding political issues.Previous research has indicated that media exposure can have a profound impact on individuals' political beliefs and actions [30] [31].In the context of political polarization, the influence of the media becomes particularly salient, as it can contribute to the widening divide between partisan groups.
Both CNN and Fox News have been found to shape the attitudes of their respective audiences through their editorial choices, framing of issues, and partisan commentary.Studies have shown that exposure to ideologically aligned media outlets can reinforce existing beliefs and attitudes, leading to increased polarization.
Moreover, the media's influence extends beyond shaping attitudes and beliefs to influencing public behavior.Research has demonstrated that media consumption can impact individuals' political participation and voting behavior.
However, it is important to acknowledge that the relationship between media exposure and public attitudes and behavior is complex and multidirectional.While the media can reinforce existing beliefs, it is also influenced by the preferences and demands of its audience [32].Media outlets may tailor their content to cater to their viewership, resulting in a feedback loop where media and audience preferences reinforce each other.
Exposure to ideologically aligned media outlets can reinforce existing beliefs, deepen partisan divisions, and influence political participation.However, it is crucial to recognize the reciprocal relationship between media and the audience, as media outlets also respond to the demands and preferences of their viewership.

Limitations and further expectations
Although this study provides a preliminary comparative study of the impact of CNN and Fox News on political polarization in the United States, there are some limitations.
First, this study is limited to two media outlets, CNN and Fox News, and does not consider the impact of other news organizations on political polarization.Future research could consider more media outlets to get a comprehensive understanding of the media's contribution to political polarization.
Second, this study relied intensively on narrative and thematic analysis to analyze CNN and Fox News coverage.However, media consumption is a dynamic process that is influenced by individual experiences, social context, and other external factors.Further research could employ more diverse research methods, such as longitudinal studies, field observations, and quantitative methods, to gain insight into the interactions and influences between media and viewers.
In addition, this study could extend the exploration of the relationship between media and political polarization.In addition to the media's influence on viewers, further research could explore the feedback effects of political polarization on media coverage.For example, political polarization influences the media's stance and reporting style, thus creating an interactive relationship.
Future research could also delve into the impact of the diversity of media consumers and the trend toward customization of media on political polarization.People are increasingly inclined to choose media that match their positions and preferences when accessing news and information.Thus, the research could explore how factors such as individual differences, social factors, and technological developments interact with selective media access to further exacerbate or slow down the trend of political polarization.

Conclusion
CNN and Fox News are known to have different political biases, with CNN being perceived as having a liberal or left-leaning bias and Fox News as having a conservative or right-leaning bias.It is not uncommon for news articles to reflect the bias of the source, so the articles from CNN and Fox News may present different perspectives or interpretations of the same news story.
In terms of the specific articles provided, the CNN articles focus on President Biden's plans to reduce carbon emissions and promote electric vehicles.They discuss the impact of proposed regulations on the auto industry, the potential benefits of electric vehicles, and the challenges in transitioning to cleaner transportation.While the articles are critical of the Trump administration's rollback of environmental regulations, they also acknowledge the difficulty of achieving significant changes in a short period.
The Fox News articles also cover Biden's policies regarding electric vehicles, but they take a more critical stance, portraying them as a "power grab" and suggesting that the administration is punishing people who choose not to purchase electric vehicles.The articles are more focused on the perceived negative effects of the proposed regulations, such as increased costs and reduced freedom of choice.
Overall, based on these articles, it appears that the CNN articles present a more optimistic perspective on the potential benefits of electric vehicles and the importance of reducing carbon emissions.The Fox News articles, on the other hand, are more critical of Biden's policies and present a more skeptical view of the benefits of electric vehicles.

Table 1 .
The Random Number

Table 2 :
The Number of Selected Passages

Sampling and Data Collection Fox
News and CNN were chosen as the targeted research object because they are two of the most widely recognized news networks in the United States, and they are known to have different political biases.CNN is a news-focused cable television station that broadcasts in the United States.It covers a variety of news subjects, including politics, business, health, technology, entertainment, and foreign news.People in the United