There's really nothing preventing state legislatures from assigning electors now, just that all 50 states have laws requiring them to go to the winner of the popular vote in that state and it's such a radical position to repeal it that even the Republican Legislatures and Governors aren't willing to. Someone like Mastriano would be willing to buy still unclear if he could get such a bill passed.
Repealing it after the election would probably be struck down by even the most conservative court as an ex post facto law and we saw how interested courts were in Trump's post-election attempts. Still any case that would potentially push gerrymandering even further is quite worrisome.
Why couldn't they just pass a law
today saying "the state's presidential electors will be determined via popular vote; however, a majority of the legislature, within three weeks of the election, may override this and determine the presidential electors" if they passed it before the election?
There's nothing in the Constitution that says they couldn't do that.
