Who's the incumbent?

2010 is likely to be a very difficult election year for Democrats nationwide.  The national political environment will affect state elections, too.  But how do they affect state elections in which the Republicans are the incumbent party?

I'm curious about this for California, where the Republicans have held the governor's mansion since 2003.  And keep in mind that as bad as the political and economic situation seem in Washington, they're far worse in Sacramento.  So, if the race comes down to Meg Whitman and Jerry Brown, who benefits by being the party out of power?

So far, it's looking like a tight race.