In Why We’re Polarized, Ezra Klein explains the causes of increasing political polarization within the Democratic and Republican Parties in the United States and argues that the consequences of this polarization are problematic due to the system of governance in the United States. Klein, a respected political journalist with a degree in political science, has the knowledge and experience to contribute this nonfictional work to the literature on US politics. Originally published in 2020, the book became a New York Times bestseller and was reviewed favorably in influential publications.

All quotations and references in this guide are from the 2021 paperback edition.

Summary

In the first half of the book, Ezra Klein details the history of polarization within the two primary political parties in the United States. In the 1950s, the Democratic and Republican Parties were not polarized but ideologically diverse. Split tickets, with voters choosing one party for Congress and the other for president, were common into the late 20th century. Yet by the end of the 20th century, the political parties had sorted ideologically. With civil rights prominent on the agenda, the Democratic coalition, which included white Southerners and African Americans in the Northern US, could not hold. Over time, Southern, conservative, white voters shifted their allegiance to the Republican Party, while a smaller group of liberal, Northern Republicans moved to the Democratic Party. With the political parties more ideologically consistent, independent voters began to gravitate to one party or the other. By 2000, only 7% of the electorate was considered undecided.

In the 21st century, these increasingly polarized parties divide over race and religion. Diversity is concentrated in the Democratic Party, with the Republican coalition predominantly white and Christian. Republicans are more likely to come from rural areas, while Democratic candidates perform better in urban settings. Given the significance of race, religion, and home to identity, the members of each party look upon the other with disdain. Increasingly, people, especially those who follow politics closely, view political participation as an expression of identity.

Klein explains that the tendency to support one’s group and treat outsiders with hostility is rooted deeply in human psychology. People act to preserve the status of their group. Aligned with race, religion, geography, and, to some extent, gender, partisanship has become a mega-identity. Any threat to these identities thus reinforces partisanship. With all identities combined, the stakes of losing are elevated. Partisans are therefore not interested in deliberation but in defending their group’s position. Reference group information, such as an endorsement by one’s own party, takes precedence over policy. For example, Republicans opposed President Obama’s healthcare proposal in 2009 even though they previously supported the policies contained within it.

When identity is threatened, Klein explains, reasoning is most likely to be sacrificed. In the 21st century, changing demographics create a context that is threatening to groups in the Republican coalition. For example, white voters are told that they will be a minority in the United States by 2045. Research shows that when white voters are confronted with evidence of increasing diversity, they are more likely to support Republicans. Barack Obama, as the first African American president, was a reminder of these changing demographics and became a divisive figure. In 2016, Donald Trump appealed to the fears of those whose racial and religious identities are shrinking as a percentage of the total population, namely white Christians, and cultivated racial resentment. Obama, in contrast, built a diverse coalition in 2008, appealing to the hope for inclusion of those previously excluded from power.

In the second half of the book, Klein explains that when a polarized public interacts with polarized political institutions, the result is more polarization. The news media covers items that elicit passion, such as conflict or outrageous statements on social media. Such stories typically trigger identities. The effect of this type of coverage is that it leaves the audience with the impression that the political parties are more polarized than they are. That, in turn, causes members of the parties to fear the members of the other party to an even greater degree, increasing polarization.

Candidates add to polarization as well. Given the small percentage of undecided voters, candidates do not focus on persuading those individuals. Instead, they seek to mobilize their base. To excite their base, they attack and demonize the other party and take positions more to the right in the Republican Party and left in the Democratic Party.

Klein argues that the consequences of polarization are dire given the US system of politics and governance. Unlike most democracies, party officials do not have a role in choosing nominees for the presidency and Congress. Members of the party choose candidates in primary elections, which have low turnout and draw ideological voters. As a result, divisive candidates have a good chance of winning. With a system of separation of powers, the Constitution depends on cooperation and compromise to function. With polarization, that is no longer happening, as the minority party seeks to displace the majority party and therefore refuses cooperation. Partisans view cooperation as a betrayal. Additionally, the minority party has tools to obstruct the majority party, such as the filibuster in the Senate. Once used only occasionally, that tool is now used routinely to block the passage of bills. The total impact of these incentives can result in disasters, such as a refusal of the US government to pay its debts.

Klein highlights the ways the Republican Party differs from the Democratic Party and is the bigger threat to the functioning of the government. With a diverse coalition, Democrats are not as ideologically cohesive as Republicans, and its members indicate a preference for moderation. Democrats are respectful of constitutional norms and more likely to compromise. Before Trump entered the political scene, Republicans were refusing to cooperate with the Obama administration, unwilling to acknowledge facts, and adopting a confrontational attitude toward the Democrats. Trump exacerbated these trends. The homogeneous coalition, which is primarily white and Christian, is attuned to threats to identity and is more likely to get news from ideological sources. Candidates and a sympathetic media remind Republicans of those threats to energize them. Although this base is shrinking as a percentage of the population, Trump and other leaders have retained a mobilization strategy. Because the coalition is based in rural areas, it is overrepresented in the constitutional system. That bias has allowed the Republicans to stick with this strategy and not try to expand their base. If this continues, Klein worries that there will be a looming crisis of legitimacy.

While not as confident in his prescriptions as he is in his diagnosis of polarization, Klein calls for partisan balance and democratic reforms, such as the abolition of the electoral college. An example of reform would be to remove the need for Congress to vote to increase the debt limit, as a failure to do so would result in economic catastrophe. With no such reforms implemented by the publication of the paperback edition, Klein observes that Trump’s claims of a stolen election in 2020, with no basis in fact, are believed by two thirds of Republicans. This statistic is a testament to the strength of partisan identity and the challenges it poses for democracy.