Couple things.. first off, a judge has to conduct a trial according to certain standards and has to justify many of the involved decisions. Failing to do so could result in an appeal throwing the trial out and professional/legal sanctions for misconduct. Judges aren't just wizards who can make any crazy decision they want. The same types of checks on accountability and adherence to the rules exist to protect Trump from Hispanic judges as do protecting him from a Hispanic surgeon doing his surgery or a Hispanic accountant managing his money.
And as an aside....what's that say about Trump's view of his own proposals? Apparently there's something about them he expects to deeply offend a certain race of people, so much that he fears professional judges will risk their careers just to get back at him. He must be aware of something really wrong with it.
Think of it this way, to see the insanity of this situatio...are defendants in all trials now somehow entitled to judges with backgrounds and beliefs similar to thiers? An openly racist black guy can't have a white judge, a pedophile can't have a judge who has children and openly cares about them, a skinny suspect can't have a fat judge? This is not Trump requesting removal of a single judge with a specific conflict uniquely deleterious to him, it is Trump requesting installation of a type of judge uniquely favorable to him.