I disagree. This city was in the midst of some serious Rudy fatigue, tired of his messy personal life.
On 9/10, he was a lame duck looking for a legacy.
If you remember, there was a lot of support at the time for scrapping democracy and extending his term.
His personal life had very little (if anything) to do with "Rudy fatigue." Let's look at the context, a tough-nosed and fiscal conservative mayor in liberal NYC. Not the suburbs, liberal NYC. When faced with a crime crisis the libs were happy to bring in a law and order salvation, but once the problem was solved then many of them were going back to their old ways, wanting someone to pursue more liberal agendas. Plus when times are good people have a natural inclination to start taking things for granted and getting restless for change. The same way the UK dumped Churchill after WWII and the US gave Bush 41 sky-high ratings after the Gulf War but then voted him out soon after.
I was in north Jersey when he was running for Senate, and he was in the lead before he dropped out. If he had a 40% approval in NYC in 8/01 (and remember that was a prety much a low ebb in the ups and downs, GOP approval ratings always go up as elections near and voters are faced with just 2 choices) then it means he would easily win statewide or nationally, given how liberal NYC is. Virtually all of those with "Rudy fatigue" felt that he was too conservative, not too liberal.
I didn't notice any "Rudy fatigue" prior to 9/11. I'm sure he could have been re-elected.
Many liberals in NYC -- and there are a lot of them -- considered Giuliani slightly to the right of Hitler prior to 9/11. I remember Susan Sarandon in front of the Brooklyn Museum denouncing Giuliani after he threatened to pull the museum's funding when they displayed a painting of the Virgin Mary decorated with pornographic cutouts of vaginas and anuses. (This was the famous "elephant dung" painting, but the media somehow never mentioned the porno collage element.) Still, I think a lot of people, even here, considered Giuliani a hero for calling the museum to task.
I disagree with the last part -- he HAD a legacy already -- but you're right, I still don't think he could have been re-elected. People were really sick of the soap opera that his life had become, and the story-line was so unflattering to his character.