I don’t think they were banned because of their support for a RINO. It’s that they got so insultingly shrill about it. They were in such a blind panic over the prospect of She-Who-Must-Not-Be-Named getting into office that they lost their senses.
The Romney followers tend to be almost cult like in their devotion to the man and it often leads them to an angry, bitter, posting style that sometimes gets them banned, not to mention that they support someone that should not even be involved in republican politics.
Scozzafava/Romney 2012