There is no way to know. Blacks could just as easily say that "they" get imprisoned for crimes and white boy there gets away with it. All the pandering Trump and the rest of the GOP did to blacks achieved exactly nothing, while the Latino vote for Trump went +10% even though he did nothing for that.

I can say that it's a risky strategy for the regime. Not necessarily because Trump will become more popular as a result (there are a lot of normie morons who think that an indictment means that you are guilty), but because this will permanently embitter Trump supporters from the regime. And if he manages the won, this time he will really go after them.