Carly Fiorina: Vote For The Sheep

This is the most recent campaign ad from Carly Fiorina, candidate for the Republican nomination in California's senatorial election, and she takes a strong whack at her opponent Tom Campbell. I find Jonthan Chait's analysis very compelling:
The funny thing about this ad, aside from the clumsy over-the-top quality, is the metaphor. The message of the ad is that Campbell is an ideological deviant. All the other Republicans signed Grover Norquist's no-taxes-ever pledge, but Campbell refused. Campbell went off on his own and made a budget deal in order to prevent a fiscal collapse. And what's the metaphor the ad uses?

Sheep. But not in a disparaging way. The good politicians are sheep, doing what Grover Norquist tells them to do. Campbell, the ad tells us, is only pretending to be a sheep, but he's really a wolf. So vote for the sheep.
Perhaps the Fiorina camp is grasping at straws because she appears to be losing...