Don't really see it. It would have to be a state that's getting more rural or something, with not a lot of swingy voters, where there is also Republican room for growth.
I guess I'll go with Vermont being the most likely to swing marginally in Trump's favor under the above scenario. Delaware would be another contender IMO but Biden's from there so that's not happening.
Clinton lost a ton of votes to third-party/Bernie write-ins in Vermont. There’s no way Trump improves his margins.
Note that I am assuming that’s what the topic is about. Swings in margin, not performance toplines.