My conjecture, for fwiw, about Trump's racist rants against the judge hearing the fraud cases against him, is that they are strategic, aimed at distracting the media, and voters, from the underlying claims against his fake university and business practices. For Trump, racism isn't a bug, but a feature of his campaign, and he is well aware that racist attacks actually bond his voters more closely to him. But he also fears, and I believe rightly, that revelations that he is a fraud, a con artist, a litigious thug and much less wealthy than he pretends to be, might peel at least some of those voters away.
On the other hand, it is more than likely that many of his core voters are not going to be shaken by proof of Trump's frauds. They would probably support him all the more, figuring that anyone smart enough to trick some poor saps out of their money (not them, of course) is worth admiring. Heck, they would probably pay top dollar for Trump seminars to learn how to do it themselves.