Actually, the ballots would be for electors pledged to Joe Biden, not the Democratic Party. The Supreme Court ruled, earlier this year that electors must vote for the candidate to whom they are pledged.
The Supreme Court ruled, earlier this year that electors must vote for the candidate to whom they are pledged.”
Actually, the Supreme Court ruled that states can require electors to vote for the candidate to whom they are pledged. The case was about “faithless elector” laws. But the state legislature could change the law to allow the electors to vote for another candidate, or the law could have a clause covering a case where the candidate dies or cannot serve. The Legislature could even choose to send its own slate of electors. The Constitution leaves it pretty much up to the Legislature.