You may have missed #38.
The states may always be free to do as they please with voting for local candidates and issues, but the federal statue concerning federal issues is, at least for the moment, applicable.
The Special Session following each presidential election is the place to determine whether the states are proceeding in this instance in direct violation of federal law. If they are not, the certificates of those states can be rejected, i.e., its total election results ignored.
All it takes is for a number of uncompromised politicians to rise and enforce the law. It could be done, with compelling evidence, during the session scheduled after the next presidential election.
Here in Arizona they actually prosecuted a former San Luis government official for vote harvesting questionably eligible ballots. That area is full of non-citizens.
Unfortunately, that is a drop in the bucket. Proof of voter eligibility should be required at the poll on the day of the election.