Consider what Saul Alinsky wrote and what Hillary and Bill imbibed. I would not discount that possibility that at least some of the would be "big tenters" are one of the following:
1) Not, in real life, part of the GOP or any other party of the Right. Agents provacateurs - imposters who are Leftist operatives in real life.
2) Officially part of the GOP, but here on evil missions. True moles of the worst kind. Working in reality for the Left but under deep cover, disguised in public life as "moderate" Republicans or, at their utmost, perhaps even further to the Right in appearance.
You got a great point. I have often said that IMO Democrat moles run the California Republican Party.
Why? Look at the Republican Party's recent performance. Such as the opposition to the recall -- then after realizing it was working the Party did jump in with "star power" and stiff-armed aside the hundreds who worked tirelessly to collect enough signatures even without Issa's million dollars.
Also, it was eye-opening to see the differences between Dems and Reps as the recall was debated. The short version is the Dems see politics as 24/7, wall-to-wall -- even maintaining something akin to baseball's farm clubs, the military's reserves, and even an enemy's "sleeper cells." Why wouldn't they put moles in the enemy's camp?