Trump has turned that distinction on its head. He’s willing to legalize the “dreamers”—who came to the United States illegally—so long as the number of legal immigrants goes down. He has not only blurred the GOP’s long-held moral distinction between legal and illegal immigration. In some ways, he’s actually flipped it—taking a harder line on people who enter the U.S. with documentation than those who don’t.
What explains this? Trump’s great hidden advantage during the 2016 Republican presidential primary was his lack of support from the GOP political and donor class. This allowed him to jettison positions—in support of free trade, in support of the Iraq War, in support of cutting Medicare and Social Security—that enjoyed support among Republican elites but little support among Republican voters. He did the same on immigration, where the “legal good, illegal bad” distinction turned out to be much more popular among the party’s leaders than among its grassroots. Cribbing from Ann Coulter’s book, Adios America, Trump replaced the legal-illegal distinction with one that turned out to have more resonance on the activist right: The distinction between white Christian immigrants and non-white, and non-Christian ones.