The most interesting question in the CNN poll, though, focused on views of American diversity. Here, the divide between younger and older Americans was clear: Younger Republican primary voters were more likely to see the increased diversity of the U.S. -- "having an increasing number of people of many different races, ethnic groups, and nationalities in the U.S.," as the question put it -- as enriching American culture rather than as a threat.

Among Republican primary voters 65 and over, a majority said this increased diversity was a threat. Among those under 50, views ran more than 2 to 1 in the opposite direction.

Trump clearly hopes to stoke this sentiment. Here, the chicken-egg situation is more clear. Even in the 2016 primaries, concerns about perceived discrimination against Whites was a better predictor of support for Trump than economic status. Trump unquestionably leveraged this sense; it seems clear that he shares the concern. (Just this week, he declared that he was facing possible indictment in New York because the prosecuting D.A., a Black man, was "racist.")

We can follow the logical chain here. If you think that America is being eroded by increased diversity, you see a less-diverse America as a better America. In that context, what does "making America great again" imply?