If cheating is proven true in the swing and other states and Biden didn't have enough legal votes to win it will be devastating to the Dem. party in '22.
True there is nothing in the Federal Constitution about removing a POTUS outside of impeachment but, that's what can happen in '22
The other way it can happen is there is legal grounds in many states that can call for a new election if fraud is found in an election. The states can decertify Biden's electoral votes and certify them to Trump or run a re-election and open a lawsuit for SCOTUS to decide on the legality.