"How Democracies Die" goes into this in quite a bit of detail. Once the fascists start breaking the rules, there's a terrible temptation to start fighting back in kind, violating norms like the one against politically motivated prosecutions dictated by the executive branch, which it's easy to decide it's time to start breaking, because we have to do something or else they might take over the fucking country. Breaking those rules is one of the last stages in the collapse of the democratic system which will hasten the fascist takeover, though. It must not be done. As counterintuitive as it sounds, you have to fight the uphill battle continuing to obey the rules against people who are breaking them. It sucks but in most cases it's the only move that leads to any good outcome.

Biden is doing the right thing by staying out of the prosecutions and letting the DOJ for some awful fuckin reason handle them at the same glacial pace that it handles everything. Why they're doing that, I don't know, but Biden is right to stay out of it.