Color me wrong.
The GOP establishment should have no qualms about condemning Dede Scozzafava's decision to endorse the Democrat in the race. What's more, her decision makes it clear that her withdrawal from the race was less an act of principle than one of cowardice -- she didn't want to take the walloping that surely was coming.
Republican moderates love to perceive themselves as denizens of the "big tent." Fair enough -- but they need to live by that tenet themselves. So far, I've found precious few who do . . . and until that day, on what grounds can they rightfully demand that conservatives behave differently than they themselves do?