Is is wrong to campaign for someone out of state? I think the point is NO ONE wants a cheater, if Trump stoops that low (which I have seen no evidence of, but if he does it will be Clintonesque territory).
No, I don’t think so. Campaigning is one thing. Voting in a caucus is another. I have seen several people say they were going to Iowa for the caucuses.
You’re right. This is the kind of thing democrats do. IIRC, Ron Paul’s supporters pulled a similar stunt in several locations
I’m sure if something like that happens, it will be talked about, no matter who does it.