Immigration is back in the news, thanks to Donald Trump. He has sparked attention by arguing that people who entered the country illegally should be rounded up and expelled and that birthright citizenship should be revoked, a proposal (briefly) echoed by Scott Walker. Neither of these things will happen. Deporting 11 million people is too expensive, and birthright citizenship is rooted in legal and constitutional norms going back to the Civil War. But the interesting thing is not the proposal but the amount of attention it received. Why?

In an informative article in Vox, Dara Lind argues that Trump appeals to anxieties that are disregarded by nearly everyone in the political elite, including the other Republican candidates. Citing academic studies, Lind shows that the public debate about immigration—which focuses on the effect of immigration on jobs—overlooks what many Americans, and most Republicans, care more about: culture. Many Americans—and not just right-wing Republicans—see immigration as a threat to their cultural identity, and that is what they are afraid of. Indeed, they are not terribly worried about the effect of immigration on jobs; “jobs” has become code for “culture.”

Mainstream politicians use this code because it is hard to mention culture explicitly without sounding racist. Most immigrants living in the country illegally are Hispanic, so an argument against illegal immigration on cultural grounds sounds like a rejection of people who speak Spanish and worship in Catholic churches. Such arguments can’t be, and aren’t, made in polite society.

Yet Americans do care about culture, and this is not something to be embarrassed about. Consider liberal cultural values that (I suspect) most readers of Slate share. Liberals value artistic expression, tolerance for minority sexual practices, and religious freedom. They don’t like guns, evangelical religion, and macho posturing. They believe that eccentric behavior should be tolerated as long as it doesn’t harm anyone. A large influx of immigrants from, say, Saudi Arabia could transform a culturally liberal neighborhood into a religious neighborhood where women wear veils and the call to prayer rings out five times a day. Whatever they say about the value of diversity, liberals don’t really want to live in such a place. Indeed, Europeans have had to confront just this threat to their liberal values, as conservative Muslims from North Africa who have settled in Europe refuse to abandon values and practices that Europeans reject as sexist, patriarchal, and intolerant.

Of course, the Americans who oppose immigration on cultural grounds tend not to be liberals. Their cultural values differ. Many, for example, emphasize self-reliance (and oppose gun control and welfare); evangelical Christianity; and military virtues such as discipline, obedience, and loyalty. Whether you share these values or not, people who hold them are just as entitled to defend them as liberals are entitled to defend their own. If they believe that immigration threatens their values, their arguments should be taken seriously. Trump, alone among the candidates, seems to realize this. As a friend who witnessed a Trump rally in Phoenix said to me: People said they worried about jobs and crime, but they were clearly angry “because supermercados are opening in traditionally white neighborhoods across Arizona.”

In an influential but much criticized book that many people saw as xenophobic if not racist, Samuel Huntington took this argument a step further. He argued that through most of its history, American culture has reflected the rather specific cultural values of English Protestant dissenters who settled this country in the 17th and 18th centuries. Their values emphasized work ethic, individualism, personal responsibility, and other virtues that—as Max Weber argued—underlie capitalism as well as the American style of liberal democracy. Huntington saw the influx of Catholic Hispanics in the 1980s and 1990s—with legal permission and without—as a threat to American culture. Catholicism, in Huntington’s telling, disapproves of money-making, makes a virtue of poverty, venerates tradition, and tolerates authoritarian governance. And while immigrants in earlier waves adopted American values, Huntington feared that Hispanic immigrants would by their sheer numbers be able to maintain communities in which those values did not prevail.

We don’t need to agree with the details of Huntington’s argument to see that he may have a point. Numerous academic studies show that cultural values influence political values and economic prosperity. In these studies, Protestantism plays less of a role in determining economic and political outcomes than Weber thought, and the story is a lot more complex. Some scholars believe that certain cultural values—including those that touch on the role of women and on the nature of political authority—can be traced to the agricultural practices of preindustrial groups from which we moderns descend. Major events—like imperial conquest, slave-raiding, and war—can produce lasting cultural effects as well that over the long term can result in illiberal, corrupt, and unstable political institutions.

If a huge influx of authoritarians, or conservative Muslims, or religious extremists settled in America, could it change our culture? It certainly could. Could the risk of the cultural change justify restrictions on migration? Of course.

Why don’t these risks receive any attention? One reason is that in the United States, unlike in Europe, no mass migration—not even the influx of Hispanics—has been large enough to cause a fundamental change in cultural values, at least not at a national level (as opposed to some local cultural shifts, for instance in Miami). The country is vast and diverse; and because it welcomes most immigrants, they or their children tend to assimilate, unlike in Europe, where many migrants live in enclaves that preserve the language and cultural values of their forefathers.

But there is another reason why these issues are not discussed. Culture is taboo because of its association with white supremacy—which is one of the reasons people accuse Trump of racism—and because of the very diversity of this country. That diversity means a diversity of cultures and a diversity of views about what our culture should be. If Congress tried to pass a law that required immigrants to adopt American cultural values or that blocked migration by those who rejected our values, it would get bogged down in an endless and vituperative debate about what those cultural values are or should be. Immigration legislation has avoided the question of cultural values by providing for immigration based on economic contribution and family connections and restricting the fraction of immigrants who can come from any single country.

If Trump is right that cultural values matter and should be part of the immigration debate, there is plenty of reason to doubt his (and Huntington’s) claim that immigration threatens American values. The studies I cited above show that values change extremely slowly; Huntington’s ominous predictions about the impact of Hispanic immigration have not come to pass. All this shows that defenders of immigration might do best to thread their way through the minefield of culture—to argue that immigration does not harm American culture and probably enriches it—rather than pretend that these concerns do not exist.