I have to wonder what will happen when McCain and Romney start running ads pointing out Giuliani’s previous record of liberalism, his chumminess with Clinton, etc. This could cause him to fall.
Having said that, if RG is the GOP nominee anyway, I would support him over any Democrat. I would just be wary after he became president. :-\
With Giuliani gaining 8 points in the last week in spite of numerous MSM hit pieces attacking him, I think the guy is pretty much immune from attack. He was inoculated the day his city was devastated by terrorists, and any hits targeted at him will backfire on the attacker. We are already seeing evidence of that.
Whoever wants to beat Rudy will have to generate some positive reasons to support the alternative, not the least of which will have to be a demonstrated ability to beat the Dim nominee in the general. I don't believe it will happen.