That's part of it. The main reason is that African Americans and Latinos are approximately as conservative/liberal as whites on ideology. But they have traditionally voted identity over ideology for Democrats. Because they rightly saw that they had an actual place at the table and voice with Democrats and Republicans treated them like crap.
It's not 100% clear why, but that is peeling away and they are voting now more in line with ideology. There are a lot more gains to be made by republicans too if it happens.
And it's not just race, you can say the exact same thing for union members. Who ever believed that most longshoremen and teamsters were motivated by progressive politics? They weren't, they voted Democrat because Democrats were for unions. But now union members are voting their ideology.
Quite a realignment going on.