So, in general (really responding to more in general up thread and not this specific post), each state has a law on the books that the party's chose their electors and once the state has official certified the election (by sec of state?) then those are the electors. The Fox New pundit guy is wrong in a way. The state legislature can't just upend that. They COULD however change the law, but luckily the Governor of Penn, Wisc, Nev, and Michigan are Democrats and would veto it.
The scenario that has never been tested is the following:
November 3. Following state law, the state of East Mississippi, holds an election. Donald Duck gets 60% of the votes, Mickey Mouse gets 40% of the vote. By state law, the secretary of state of East Mississippi declares that the electors supporting Donald Duck are appointed.
Then, on November 10, the legislature convenes, and the Rodentia party has a majority of the legislative seats, and they pass a law that says, "This year, all electors from East Mississippi must vote for Mickey Mouse."
At that point, are the electors required to vote for Mickey Mouse?
I think that the Supreme Court would rule that they were not. I think they would rule that East Mississippi must follow the law that existed at the time the election was held, and that the Donald Duck slate of electors was appointed, and they would vote however state law, as of November 3, said they would vote.
That's not quite as extreme as the case Larry Elder was yapping about. Suppose a state has a law, and everyone agrees on the election law, but during the count, massive evidence of fraud is discovered. The real, legal, votes, are impossible to reconstruct fairly. Could they, in that case, get together and say that it is their opinion that in a fair election, Mickey Mouse would have won, and therefore the electors for Mickey Mouse are appointed?
That's what Elder is advocating in this case. He's saying that the legislature should jump in and declare the Donald Trump electors to be appointed, on the grounds that the election laws were broken by all the fraud, so the election results are thrown out and our guy wins anyway.
Of course in the real world, there is no massive evidence of fraud, and I think it would be thrown out, and the state would be ordered to seat the electors appointed in accordance with the certified election results. In other words, I think that Larry Elder is a crank.