There's a long tradition of candidates running for the Presidency simply to make a point or "get their issue out there" before the voters.
I agree that that alone would be a favor to the GOP this year. And as I pointed out to Tom, with so many open primaries in 2012, the Tea Party may not have quite the lock on the GOP that we're assuming.
What if Democrats decided to help out the GOP (and the country) in 2012 by voting for a moderate Republican in those primaries?
I voted for McCain in 2000, the last time California had an open primary. The law was changed, then changed back, and I could do it again in 2012. It's worth considering.