Giuliani ran the largest city in the United States, with a police force larger than many militaries, and has an executive track record. He had more on his plate than many governors, and they get elected all the time. It's not like he was the mayor of Bokipse, Minnesota.
Fred Thompson is right on the issues, but very light on experience. Senators do get elected President, but his term was both short and unremarkable. He's a nice guy with a little political experience and a modest acting career. Reagan was govenor of California, and president of the Screen Actors Guild. That's executive experience, and quantifiable leadership. Thompson simply doesn't have that under his belt.
What does it really matter what city it was? Like I care, or anyone else for that matter, any more or less, or his experience is any better, than it's already-dismal state, because he ran New York City!
Probably one of the few cities that would have elected this clown pre-9/11. Gay-loving, anti-second amendment, pro-illegal alien, pro-abortion crossdressers wouldn't play to well in the south or midwest.