Following up on Jennifer’s post, it’s important to note that while Giuliani’s polling may be stable, his lead has been shrinking relative to his rivals, and is down to 4.6 percent in the RCP average. Also, several polls do show a rather dramatic errosion in his support. In the NY Times/CBS News poll, Rudy dropped 11 points since August and in this Washington Post/ABC News poll, he dropped 9 points since July.
There are several possible explanations for this. One is, as noted below, the Thompson post-announcement bounce, and we’ll have to wait and see whether it is short-lived. Another is the McCain resurgence, which is likely coming as a result of his strong stand on Iraq, possibly taking national security voters away from Rudy. Yet another–which would be the worst possibility for Team Rudy– is that the long-standing prediction of Giuliani critics that Republican primary voters would reject Rudy once they learned more about his liberal positions could be coming true. Did the sanctuary city battle be hurt Rudy? What about his assertion that illegal immigration shouldn’t be a crime? We’ll have to wait and see. Also worth noting is that while the sanctuary battle may have hurt Rudy, it certainly didn’t help Romney. After enjoying a post-Ames bounce, Romney has begun to fade in the national polls again, resuming his position in the low double-digit range.
UPDATE: A Rudy friend notes that the recent USA Today/Gallup poll showed Giuliani with a sizable 12-point lead.