Personally I don’t understand these kind of people either, who endorse something that directly goes against themselves (e.g. in case of gays in conservative parties) or their children. But I think there also is another way to view this behavior:

Because besides being a father of biracial children, he is one other important thing: rich. And he only gains to get richer from playing towards the maga crowd.

So how much do we actually expect his children to suffer the consequences? They’ll probably grow up privileged in good neighborhoods, get great education, own their homes and advance in their careers through connections.