I have been thinking about this alot since the last election. I have to agree.
In my case there wasn't even a Republican CongressCritter on the ballot. The Democrat primary is where the real action is. I don't think the Donner Party is where McCain rejectors are either. McCain rejectors won't cannibalize each other. Remember that the Constitution is silent wrt political parties and that that the two major parties have changed over the centuries and are likely to do so again (Do you believe in Global Warming too?). The US will survive Hitlery!, like we survived her better half.