The only way a dictator gets stopped is through violent overthrow. We don’t do that in this country, and our system has no way to handle this. The courts can act, but would he even respond to the courts. His history says no.
Our system does have a Constitutional way to handle this and it via impeachment. Nothing else will stop him and that’s why impeachment is in the Constitution. If the GOP doesn’t have the guts to do it..well that is why we have the 2nd Amendment.