Why Do Blacks Support Biden?

In his Wall Street Journal column Jason Riley attempts to explain something I have been trying to explicate for some time:

Your typical black Democratic primary voter is likely to be middle-aged and female, and right now Joe Biden is her guy. But who’s her second choice?

There is general agreement that black voters, while a small percentage of all voters, could again play an outsize role in determining the Democratic presidential nominee and the outcome of next year’s election. Blacks are concentrated in important primary states, such as South Carolina, as well as in the cities of key battleground states like Michigan and Wisconsin.

Perhaps taking them for granted, Hillary Clinton failed to mobilize enough black voters in 2016, when black voter turnout fell in a presidential election for the first time in 20 years. Mr. Biden believes he can succeed where she failed, and perhaps he can. His popularity among blacks obviously stems from his eight-year stint as Barack Obama’s vice president. He is quick to invoke Mr. Obama’s name in front of black audiences and to defend their administration’s policy victories, such as ObamaCare. Mr. Biden is also more politically moderate than most of his rivals, which sits well with older blacks who are more likely to vote.

Blacks are more conservative than Democrats, generally, they are more religious than Democrats, generally, their rate of military service is higher than Democrats, generally, and their median level of educational attainment is lower than Democrats, generally.