Philip Bump, writing at The Fix, The Washington Post's politics blog, observes that the Democrats are splitting along racial lines, at least in the primary season. Non-whites continue to strongly back Clinton, whites are moving to Sanders and Biden.
To be a white Democrat in this era, it helps to be ideologically left. That's where Sanders lives, he speaks to white Democrats. Most whites in this era are Republicans, or perhaps independents.
Minority voters are Democrats more because it is the party that caters to them, and less because they are crypto-socialists who find capitalism distasteful. Clinton feels comfortable to these voters.
It is massively ironic that a party that has emphasized racial segmentation via interest group politics, having sown the wind, is reaping the whirlwind. We wish them the "joy" of it.