There's a significant gulf separating the ideological diversity of the Black community in the real world and the political reality that being a Black Republican means you're literally hanging out with White supremacists that will shamelessly parade you around as a prop to prove they can't possibly be racist.
Yes, theoretically, there should be a "Conservative party" to serve as an ideological counterweight to the "liberal" Democrats, and Blacks have every right to vote accordingly.
But in the real world, that's bullshit and everyone knows it.
Right now, in the age of Trump, the Democrats aren't "leftists", they're a political liferaft for every single person with a shred of decency and two neurons to rub together. The GOP is so one-dimensionally awful on every conceivable level that you pretty much have to temporarily be a "leftist by default" until an actual conservative party emerges that isn't this psychobilly nightmare of the worst human beings imaginable.
And under normal circumstances, if we were discussing whether or not something is racist, I'll usually default to the opinion of the person that's a member of that race.
But Trumpism is so bad that, no, if you don't realize these people think you're animals that can aimlessly riot for months on end and need to be put down like rabid dogs, you're a fucking idiot, White or Black.