Mr. Sanders popularity, on the other hand, is greatest among young white voters, and is a reaction to that Faustian deal the left made during the 1990s. The young white progressives who support Mr. Sanders in huge numbers are the first generation of white Americans who are very unlikely to be in a majority or have as much wealth and power, relative to other groups than any generation of white Americans before them. Bernie Sanders, while never veering into anything close to the mean-spirited, divisive and provocative rhetoric that we have seen from Mr. Trump, gives his young white base a political option that allows them to express both their economic concerns and uncertainty, and their less overt, and perhaps less realized, concerns about their changing position in American society. It is a fascinating paradox that while many, but not all, of Mr. Sanders’s positions are truly radical, they are too frequently presented as left wing riff on the tired notion that the old white guy knows best.