What's changed? For decades black America was, paradoxically, a net electoral advantage for the Republican party. Blacks were the sheet anchor of the Southern Strategy and a key part of the division in American society along which Pat Buchanan famously said the party could cut the country in half and have the bigger part. And yet suddenly, it's not clear they're an electoral advantage. Combined with Hispanics, non-white America is growing each year as a percentage of the population. And the slice of the population you can whip up into hysteria and grievance over their presence as an essential part of the fabric of America is in demographic decline.
This is all scary. It makes people do silly things.