I hope he won't be the nominee. But if it's Giuliani vs Hillary, I'll be voting for Giuliani. If you think 3rd party is a better alternative for the country, that's the way you'll go, but I'll not as I did during the electoral campaign that there are differences between Republicans and Democrats, and if collectively "conservatives" stay home, or vote 3rd party, they should do that accepting that the Republican Party will likely move left. Where the vots are. "Conservative" in quotes because I don't think most will either stay home or vote 3rd party.
I think 2008 is the GOP last major chance to reform itself and Rudi isn't the answer. Run him and Whigg will be a term used to describe the GOP's future beyond that.