Alan Abramowitz is professor of political science at Emory University. Steven Webster is a graduate student at Emory University.

If you’re confused about why a president whose campaign is under investigation for its possible ties to Russian hackers, whose approval ratings are abysmal only halfway into his first year, whose legislative agenda is already off the rails, and who launches bizarre Twitter rants each day still commands the fealty of the Republican Party, don’t be. Donald Trump thrives amid all this chaos because of the rise of a phenomenon that we have labeled “negative partisanship.”

The concept is pretty simple: Over the past few decades, American politics has become like a bitter sports rivalry, in which the parties hang together mainly out of sheer hatred of the other team, rather than a shared sense of purpose. Republicans might not love the president, but they absolutely loathe his Democratic adversaries. And it’s also true of Democrats, who might be consumed by their internal feuds over foreign policy and the proper role of government were it not for Trump. Negative partisanship explains nearly everything in American politics today—from why Trump’s base is unlikely to abandon him even if, as he once said, he were to shoot someone on Fifth Avenue, to why it was so easy for vulnerable red-state Democrats to resist defecting on the health care bill.


Consider, for instance, that while Trump’s approval ratings have lately been in the mid- to upper 30s, he has maintained support of the overwhelming majority of Republican voters—around 80 percent in Gallup’s tracking poll. And that’s what matters to him and to most Republican members of Congress. The president understands that as long as that Republican base remains loyal to him, he is unlikely to face a serious challenge from GOP members of the House and Senate. He also knows that the surest way to keep the support of his base is by attacking Democrats, especially the two most prominent leaders of the Democratic Party—Hillary Clinton and Barack Obama. What looks like an unhealthy Twitter obsession over “Crooked Hillary” and her emails is more likely a team-building exercise—a shrewd effort to keep his party focused on their shared enemy: Democrats. And so far, it’s working for him.

This hostile and confrontational style of politics is a by-product of the growth in negative partisanship within the American electorate. Our research has shown that since the 1980s, supporters of both major parties, including independents who just lean toward one party or the other, have grown to dislike the opposing party and its elected leaders more than they like their own party and its elected leaders. And judging from opinion polls, that trend reached a new high in 2016—an election dominated by negative feelings toward both major-party candidates.

Neither Trump nor Clinton was especially well-liked. Data from a Pew survey conducted before the 2016 national conventions found that both candidates received mediocre ratings from supporters of their own party—and record low ratings from members of the opposing party. On a “feeling thermometer” scale of zero to 100 degrees, Clinton received an average rating of 12 degrees from Republicans, while Trump received an average rating of 11 degrees from Democrats. In fact, 68 percent of Democrats rated Trump at zero, and 59 percent of Republicans rated Clinton at zero—an extraordinary reading with no modern precedent.

As a result, even though many voters had reservations about their own party’s nominee, very few ended up defecting in November. It was once common for voters to choose, say, a Republican for president and a Democrat for senator. No longer: Recent elections have been characterized by unprecedented party loyalty and straight-ticket voting, and negative partisanship is a major reason.

The concept of negative partisanship was first developed by political scientists studying countries with multi-party systems, such as Canada and Germany. But today, it applies even more clearly to the United States. Our research shows that Americans increasingly are voting against the opposing party more than they are voting for their own party.

And that should worry us. Dislike, even at times hatred, of the opposing party and its leaders reflects a growing divide between Democrats and Republicans over a wide range of economic and social issues. But it also reflects a growing divide over race, religion and values—a chasm that could become dangerous as partisans come to see each other not just as political adversaries, but as enemies who want to harm the nation.

And there’s a longer-term danger to our democratic system here, too, that is likely to survive well beyond Trump. In today’s environment, rather than seeking to inspire voters around a cohesive and forward-looking vision, politicians need only incite fear and anger toward the opposing party to win and maintain power. Until that fundamental incentive goes away, expect politics to get even uglier.