You can see all of the analogs to the Islamic terror food chain, in miniature. White nationalists have their terrorist actors, such as Patrick Crusius. They have their ideological theorists, such as Richard Spencer, who provide the intellectual framework for terrorism without getting their hands dirty. Russia is not exactly a state sponsor, but more like a state-sympathizer.
If you look around what has become mainstream American conservatism over the last four years, you see some people who look like Anjem Choudary, insisting that there is no such thing as white nationalism. (See Dennis Prager twist himself into a logic pretzel here, for example.) And then a larger number of people who mouth de minimis condemnations of the actual terror acts and then turn around and continue to stoke the fires of racial grievance with abject nonsense. Like Amy Wax.
And while it should go without saying, it does not help to have, as the president of the United States, a man who claims that Mexican immigrants are murderers and rapists. The statement contains perhaps a kernel of truth, in so much as there are criminals in any large group of people. But it’s certainly not true that immigrants are statistically more likely than any other group to commit crimes. And in fact, the truth is the opposite: They are less likely to commit crimes than native-born Americans.