You're also right that the Left is apoplectic that Trump did even marginally better with minority voters in the last election.
Obama-ites are also worried about an emerging consensus amongst black academics that Obama's eight years were worthless, in practical terms, to the lives of most black Americans.
Today on NPR I heard a prominent black professor, Deborah Dickerson, say something shockingly disrespectful of Obama -- it was so bad, I don't think I should repeat it here (lest the Left use it to accuse FR of being racist!).
I’ve posted before that few (if any) of the Obama pictures proudly hung by black co-workers in 2008 were still up a year later. They weren’t sure how, but they knew their brief taste of middle class life was over (buying new cars, cruises for vacations, occasional fine dining). Suddenly they were spending a lot of time checking their personal bank balances from work, trying to pay their bills and their children’s student loans, and they weren’t happy about it...