Bill Quick lays out the arguments here describing many of the reason I could never, ever vote for John McCain (I obviously disagree with Quick about immigration, but the rest are very compelling reasons).
It is more likely that I will vote for Hillary or Obama than vote for John McCain.
I agree wholeheartedly. I have never missed voting in as much as a local issue ballot. I first voted in 1986 for Ronald Reagan and have been a Conservative Republican ever since. And, I am here to tell you: I will not vote in this election if John McCain is the candidate.
http://www.iwillnevervoteforjohnmccain.com