[sam h]

I think you just have to look at individual explanations for each mayor. New York was in such trouble during the 1970s and 1980s and a lot of that had to do with the incompetence and bureaucratic bullshit of the local democratic machine. Giuliani came in basically promising to clean house. Nobody cared about his ideas about national political issues as long as he could clean up crime and get the city on firmer financial footing. Both things happened under his administration, probably more because of spectacular economic performance than his "broken windows" policies. It's important to remember, however, that people soured on his conservative stances regarding censorship, the use of force by police, and other issues. As the end of his second term approached, a majority of New Yorkers wanted him out badly and his political career looked pretty dead despite his own thoughts on the matter (he would have done better than Lazio, but still would have lost to Clinton if he had ran for senate). Then 9/11 hit.

Bloomberg is a centrist who leans left on most issues and, in a vacuum, might have run on the democratic ticket rather than the republican one. But its hard to break into democratic politics in New York as you have to please all sorts of entrenched party power brokers. He's popular in the city because he's all about the bottom line and getting things done but is closer ideologically to most people than Giuliani.