Donald Trump arrives to address his supporters after finishing second in the Iowa caucus, in West Des Moines, Iowa, on Feb. 1. (Jim Watson/AFP/Getty Images)

Presidential candidate Donald Trump’s loss in the Iowa caucuses may be in our rear-view mirror, but with the New Hampshire primary approaching, he’s still with us. And the GOP establishment and many in the media remain flabbergasted by his appeal to GOP primary voters.

Clearly, some of Trump’s supporters hold racist, nativist (and sometimes white supremacist) views. This was illustrated in a poll last week from the Presidential Election Panel Survey, in which white ethnocentrism was highly correlated with support for Trump.

That’s hardly unique to the United States. As Syrian refugees and others head north, many commentators in Europe have noted the rise of resentment toward Muslims and immigrants. Around the world, researchers commonly study how ethnic resentment can drive political views. A catalog of academic work documents precisely how ethnic resentment helps foster attitudes that promote ethnic violence.

And if you listen to what Trump supporters say, you can hear that the dynamics of U.S. ethnic resentment sound remarkably similar to those found elsewhere. To be clear, Trump’s supporters are not likely to engage in ethnic violence, but their resentment-based rhetoric sounds all too familiar to scholars of ethnic politics.

So what does political science teach us about ethnic resentment?

When does ethnicity matter?

While ethnicity is socially constructed, ethnicity can matter in every country. But it is not always the most prominent political division. Daniel Posner, Dawn Brancati, and others have shown that ethnicity matters politically when the minority group is large enough to affect elections or if the majority’s leaders need members of that ethnic group to help rule a country that’s not a democracy.

Benn Eifert, Edward Miguel and Posner, for example, surveyed 10 African countries, and found that citizens identify with their ethnic group, especially when politicians needed their ethnic group to help swing the election. In a different vein, Harris Mylonas studied the Balkan states during the 19th and early 20th centuries and concluded that when creating nations, ethnicity matters a great deal in deciding who gets defined as citizens and who gets defined as outsiders. There, Serbian leaders saw some Albanian Muslims as part of the constant overseas threat from the Ottoman Empire and used exclusionary policies to attempt to remove Albanians from the Serbian nation.

Overall, ethnicity seems to be brought to the fore when it’s politically relevant and when it’s encouraged by politicians who see that it can be useful. Sound familiar?

The biggest problem isn’t fear. It’s resentment.

In 1985, Donald Horowitz argued that ethnic conflict could emerge when one group doesn’t feel adequately represented in governmental institutions. After recognizing that collapsing nations are more vulnerable to ethnic violence, Roger Petersen found traditional theories focusing on fear of others and “ancient hatreds” between ethnic groups don’t adequately explain what causes individuals to support ethnic violence. Instead, resentment of the status of one’s ethnic group does.

Resentment arises when someone — or a group of someones — starts to feel that their ethnic group is no longer at the top of the country’s ethnic hierarchy, or never reached its proper spot in that hierarchy. In other words, ethnic violence is most imminent when formerly dominant groups lose political power — or think they will — as the nation is coming apart. Think of the breakup of the former Yugoslavia, as many Serbs resented the status accumulated by Croats and Muslim Bosnians. Slobodan Milošević harnessed this resentment to gain power, and in doing so, prepared his followers to support large-scale violence to punish those who were deemed to have usurped too much of the Serbs’ political power.

Petersen found evidence that ethnic resentment was the reason for violence throughout Eastern Europe’s history. During the German invasion in the Second World War, resentment toward Jewish minorities in Lithuania and throughout the Baltic States prompted mass violence and in some cases support for collaboration with the Nazi occupiers.

Lars-Erik Cederman, Andreas Wimmer and Brian Min found something similar when they created the Ethnic Power Relations data set, which catalogs every politically relevant ethnic group in 157 countries, ranking their access to state power between 1946 and 2010. They found that ethnic groups that recently slipped down the ethnic power hierarchy of the state were the ones more likely to engage in ethnic violence.

All this may sound like common sense, but it’s useful to know that all this evidence has a pattern. When one ethnic group loses status or its members start feeling that they don’t have the status they deserve, the group can get resentful. Nationalist politicians then swoop in to capitalize on the resentment to capture political power. And the resentment about ebbing power can make unthinkable political positions into common and even prominent beliefs.

What does this tell us about the rise of Trump?

In the United States, it’s well known that nonwhite voters are increasing in demographic numbers and political power. Feeling threatened, some white voters might seethe at the loss of their cultural dominance and political power. This resentment of ethnicities who are “taking” their political power gets expressed in statements from Trump supporters claiming “no one’s looking out for the white guy anymore,” that “white Americans founded this country” and that “we are being pushed aside.”

Of course not all, or even most, members of any ethnic group start to resent the rising status of the ethnic “other.” Not every white American resents the idea of a majority-minority country; not every Serb came to hate Bosnian Muslims; not all Flemish people hate Walloons. But why would even a subset feel enough resentment to start voicing such anger? Because in their minds, electing Trump — or Milošević, or Marine Le Pen — could restore their interests to the top of the political agenda, putting their group back in charge, where they think they belong.

All Trump is doing is tapping into this reservoir of resentment to become what Stuart Kaufman calls a cultural entrepreneur: someone who rhetorically uses cultural myths and ethnic symbols to inspire still more resentment, positioning himself as its champion, to gain followers — and power.

How will this affect the future of U.S. politics?

The United States’ demographic shifts aren’t going away. After noting Mitt Romney lost the 2012 presidential election with a higher percentage of white voters than Ronald Reagan ever had, one report predicts that in 2016, “the white share would drop from 72 percent in 2012 to 70 percent in 2016.”

And so resentment will keep simmering — or even boiling — among some white voters. Some politicians such as Trump will keep trying to use the resentment to gain power, even though the resentment will represent less and less of the U.S. electorate.

Will the United States see widespread and organized ethnic violence? No. Resentment like this hasn’t led to large-scale ethnic violence unless a nation and state’s institutions are breaking apart. For instance, the breakdown of Weimar Germany was the catalyst that allowed the rise of the Nazi party. That’s not something the United States faces even with levels of resentment rising.

Trump’s supporters are not campaigning to use violence to maintain their place in the ethnic hierarchy. But it’s useful to realize that Trump’s rise — and his startlingly non-democratic policy proposals — have so much in common with the politics of ethnic resentment elsewhere. As long as the ethnic power hierarchy continues to shift, be prepared to keep hearing U.S. politicians, Trump or no Trump, attempt to coalesce this resentment into tangible political support.

Benjamin Denison is a PhD candidate in political science at the University of Notre Dame. Follow him on twitter at @DenisonBe.