I mentioned McCain because the media are constantly mentioning him as a candidate.
No, I agree with you. He is certifiably nuts. If the choice was between hillary and McCain, I really don't know which I would vote for. Probably neither. Withholding your vote or voting third party is never useful, but if the Republicans were ever stupid enough to nominate him, those would pretty much be the only choices left.
If Giuliani were nominated, the media would kill him on the moral issues. Partial birth abortion, gay rights, messy divorces, northeasterner. Freepers might decide to vote for him, but probably ten million religious conservatives would shake their heads and stay home. I like Rudy, in spite of all his problems, but not as a presidential candidate.