Via Greg Sargent at TPMCafe, here's Stu Rothenberg on why Rudy can't win:
Does anyone seriously believe that a Democrat who opposes legal abortion could be nominated for president by his or her party?...Rudy may end up seeing the light on abortion if the polls tell him to. Still, I honestly don't believe Giuliani really would make a "terrific general election candidate," for the simple fact that he's got skeletons in his closet beyond those which particularly upset the right.
And if the Democrats wouldn’t nominate a cultural conservative, why should anyone believe that Republicans would pick a social liberal? It seems to me that you need to suspend all your analytical faculties to believe the GOP will nominate for president a Republican who supports abortion rights, and is pro-gun control and pro-gay rights. It just isn’t going to happen, at least not in my lifetime.
Giuliani’s strong showing in GOP polling reflects his celebrity status and the reputation he earned after the terrorist attacks. But if and when he becomes a candidate, that will change. He will be evaluated on the basis of different things, including his past and current positions and behavior, and he’ll be attacked by critics and opponents. A Giuliani nomination would also generate a conservative third-party candidate in the general election and tear the GOP apart, thereby undercutting Giuliani’s electability argument.
So, the former mayor might make a terrific general election candidate, but I don’t see how he can get there as a Republican.