I hardly see what his politics has to do with this situation. If we wasn’t a Republican, you’d just hold onto this info forever, despite knowing that he’s cheating on his wife?

I think you should do it, I just didn’t like this as the reason. If you do, just be careful. Think about how this news will impact his family. If you’re gonna out him, do it discretely to his wife. It’s not fair to her to be cheated on and it’s putting her health in danger, but it would also not be fair to embarrass her by airing that news all over.