I've voted Republican all my life. But now that Ron Paul has shown me the way, I can't hardly stomach to vote Republican anymore.
My second choice, unfortunately, would not be based on policy (because none compares with Ron Paul). So I would vote based on my perceived honesty of the candidate.
Guiliani? No
Romney? Not a chance
McCain? Too warmongery
Hillary? No way
I would consider Obama, Kucinich, or Huckabee......pending further investigation.
But most likely, I'd refrain from voting for anyone else. It's tough to go back to crap once you've found the "real thing".