I don't think I would be comfortable supporting a party that Orange County also supported.
If Obama wins Orange County, it's only because the Republicans nominate someone insane enough to have affluent Republicans truly fear his (or her) election. Otherwise, not happening.
Didn't he make much larger gains in the Los Angeles metro counties than he did in the Bay Area? Eyeballing some results, McCain basically performed at Bush levels in places like San Francisco, or 2-4 points behind or so in the collar counties.
Obma made large gains in some of the more peripheral suburbs, but for the most part the Democratic vote in the Bay Area is already maxed out.
