Photo Courtesy of Simon & Schuster

There’s no question that, when it comes to politics, Americans are incredibly divided. How did that happen? And what can be done about it? In this special excerpt from his new book Why We’re Polarized, out now from Simon & Schuster, journalist and political analyst Ezra Klein explores the concept of negative partisanship and why Americans’ feelings toward the two dominant parties have become so extreme.

It used to be common for voters to split their tickets: perhaps you preferred Democrat Lyndon Johnson for president but Republican George Romney for governor. And if you were a ticket-splitter, and most of the people you knew were ticket-splitters, it was hard to identify too deeply with either party; after all, you occasionally voted for both.

In a striking analysis entitled “All Politics Is National,” Emory University political scientists Alan Abramowitz and Steven Webster show how that behavior collapsed in the latter half of the twentieth century and virtually disappeared across the millennium’s dividing line. Looking at districts with contested House races, they found that between 1972 and 1980, the correlation between the Democratic share of the House vote and the Democratic share of the presidential vote was .54. Between 1982 and 1990, that rose to .65. By 2018, it had reached .97! In forty years, support for the Democratic presidential candidate went from being a helpful, but far from reliable, predictor of support for a party’s House candidate to being an almost perfect guide.

Ticket-splitting requires a baseline comfort with both political parties. Behind its demise is the evaporation of that comfort. Amid the battery of questions that surveyors ask Americans in every election lurks something called the “feeling thermometer.” The thermometer asks people to rate their feelings toward the two political parties on a scale of 1 to 100 degrees, where 1 is cold and negative and 100 is warm and positive. Since the 1980s, Republicans’ feelings toward the Democratic Party and Democrats’ feelings toward the Republican Party have dropped off a cliff.

In 1980, voters gave the opposite party a 45 on the thermometer—not as high as the 72 they gave their own party, but a pretty decent number all the same. After 1980, though, the numbers began dropping. By 1992, the opposing party was down to 40; by 1998, it had fallen to 38; in 2016, it was down to 29. Meanwhile, partisans’ views toward their own parties fell from 72 in 1980 to 65 in 2016.

But it wasn’t just partisans. In his important paper “Polarization and the Decline of the American Floating Voter,” Michigan State University political scientist Corwin Smidt found that between 2000 and 2004, self-proclaimed independents were more stable in which party they supported than self-proclaimed strong partisans were from 1972 to 1976.  I want to say that again: today’s independents vote more predictably for one party over the other than yesteryear’s partisans. That’s a remarkable fact.

Here’s what’s strange, though: over this same period, the electorate was shrugging off its party allegiances. In 1964, about 80 percent of voters said they were either Republicans or Democrats. By 2012, that had dropped to 63 percent—“the lowest percentage of party identifiers in the history of the American National Election Studies,” notes Abramowitz and Webster—with the share of self-proclaimed independents rising sharply.

On first glance, these two trends contradict: How can the electorate become both more partisan in its voting behavior and more independent in its party membership? Shouldn’t more consistent support for a party lead to a closer allegiance to that party?

The key idea here is “negative partisanship”: partisan behavior driven not by positive feelings toward the party you support but negative feelings toward the party you oppose. If you’ve ever voted in an election feeling a bit bleh about the candidate you backed, but fearful of the troglodyte or socialist running against her, you’ve been a negative partisan. It turns out a lot of us have been negative partisans. A 2016 Pew poll found that self-described independents who tended to vote for one party or the other were driven more by negative motivations. Majorities of both Republican- and Democratic-leaning independents said a major reason for their lean was the other party’s policies were bad for the country; by contrast, only a third of each group said they were driven by support for the policies of the party they were voting for.

So here, then, is the last fifty years of American politics summarized: we became more consistent in the party we vote for not because we came to like our party more—indeed, we’ve come to like the parties we vote for less—but because we came to dislike the opposing party more. Even as hope and change sputter, fear and loathing proceed.

The question is why all this happened. What changed in American politics such that voters became so reliably partisan?

Excerpted from Why We’re Polarized by Ezra Klein. Copyright © 2020 by the author. Used by permission of the publisher. All rights reserved.

Ezra Klein is the editor-at-large and cofounder of Vox, the award-winning explanatory news organization. Launched in 2014, Vox reaches more than 50 million people across its platforms each month. Klein is also the host of the podcast the Ezra Klein Show, cohost of the Weeds podcast, and an executive producer on Vox’s Netflix show, Explained. Previously, Klein was a columnist and editor at The Washington Post, a policy analyst at MSNBC, and a contributor to Bloomberg.