Well, they aren't that big relative to the state, and just like I think 85%+ GOP voting among Southern white people can not last, I also think the 85%+ Dem margins with black voters will slowly fade away. Consider what happened with the Catholic vote after Kennedy and LBJ. It went from about 80% Kennedy in a tied national race in 1960 to a swing demographic by the 1980's.
On a national scale, you can kind of see that already with African American males. However, I don't think that really has anything to do with erosion among AAs specifically but rather males in general. Female African Americans overall are very Democratic. Democrats also seemed to underperform with African American Millennials in the House vote as well. 83% - 15%
I agree that Democrats probably can't expect to hold that demographic by such absurd numbers forever, but it is unclear so far how long it will take to diminish and when that slide would start
(unless it has already with Millennials)
