Not that tough, assuming Democrats control both houses of the state legislature, and that Republicans lack the ability to filibuster in either house, and that there is no Republican governor with a veto. But there are not that many states where all of that is true.
Republican blocking that would be the kiss of death. Let the people have their representation. Remember, the only way it even matters is if Biden wins the state, GOP state legislatures in those states would be on a thin line anyway.