Some argue that lesser-educated voters are attracted to Trump because of his anti-immigration platform. Americans with lower education could be more exposed to competition from immigrant workers. But many surveys show that there is little or no correlation between opposition to immigration and exposure to job competition from immigrants. Indeed, opposition to immigration is disproportionately high in states where the immigrant population is relatively small. Moreover, the people most exposed to competition from new immigrants are other recent immigrants with similar job skills. Yet immigrants consistently show stronger support for additional immigration than do native-born Americans.

In both the United States and Europe, support for tighter restrictions on immigration is highly correlated with ignorance about the true number of immigrants (restrictionists tend to greatly overestimate it) and with xenophobic hostility toward foreigners. Opposition to immigration is also often correlated with ignorance of economics. In his book The Myth of the Rational Voter, economist Bryan Caplan found that the economists on both the left and right take a far more favorable view of the impact of immigration on the economy than ordinary voters, particularly those who have low levels of education and economic knowledge. Economists understand that the economy is not a zero-sum game between immigrants and natives; rather, each group can benefit from the work of the other.

Anti-immigration voters might also be misled by claims that immigrants increase the crime rate, an assertion embodied in Trump’s notorious statement that Mexico is sending us “criminals” and “rapists.” In reality, studies consistently show that immigrants have a much lower violent crime rate than natives. Not all opposition to immigration is the result of ignorance. But a great deal is.