Not nationally, but because Maine uses both Instant runoff voting for presidential elections, and the Congressional district method of assigning electors, it’s mathematically possibly for Maine to split its electors 2-2. eg, the Republican wins both districts individually, while the Democrat wins statewide. Not this year though – needs a competitive 3-way race so the runoffs matter.

Party affiliation as listed on voter registration isn’t a loyalty oath either. It’s just a way of asking which primaries you want to vote in. You might as well pick a party with relevant primaries in your area whether you agree with their platform or not.

(Voter registration is public information and may affect which candidates and PACs send you mail.)

I think it’s Chaucer era.