New York City will likely re-elect independent Michael Bloomberg to a third-term Tuesday. But the real story is term limits.

Bloomberg convinced, or bullied if you prefer, 29 of 51 City Council members last year to amend New York City's term limits law, despite voters twice upholding it by referendum. Mayors were restricted to two, four-year terms.

To some outsiders, Bloomberg's ambition for term three may seem unremarkable. Over in Boston, Mayor Thomas Menino is seeking an unprecedented fifth term in office. But the circumstances of Bloomberg are unique.

Bloomberg owes his election to the term-limits law. It is what forced Rudy Giuliani to leave Gracie Mansion and made Bloomberg's tenure possible. That irony must infuriate Bloomberg's opponents.

Giuliani was popular at the end of his second term, almost entirely due to his performance after the September 11 attacks. He considered extending his term after 9/11. Nationally he was America's mayor. But up close, many city voters still saw warts. Democrats long accused Giuliani of being more dictator than mayor. The mayor had earned newfound respect by late 2001. But old wounds lingered.

Giuliani ultimately decided it would be too controversial. He later endorsed Bloomberg. The Giuliani-stamp helped push the media tycoon to victory. Now it's Bloomberg who has made the power grab in a respect Giuliani desired, but dared not.

What did Bloomberg have that Giuliani did not? Billions, of course, is the primary answer. The media tycoon has spent at least $85 million of his own money. That total may rise to $100 million by the close of Tuesday. In total, Bloomberg has spent the most money of any politician in U.S. history on his bids to be merely mayor, more than a quarter billion of his own money. By comparison, in this race, his top competitor Bill Thompson has spent $6 million.

But as Jon Corzine demonstrates over in New Jersey, money cannot make everyone's bid so easy. Bloomberg is seen as an effective executive, and low key one at that (by comparison to Giuliani). “The real test of any mayor is how well the city works. In his eight years in office, Mayor Michael Bloomberg has managed to make the unpredictable city of New York work astonishingly well,” as The New York Times wrote in its endorsement.

Polls show that about four in 10 voters say they are less inclined to back Bloomberg because of the term limits issue. That's likely not enough to unseat the mayor.

The Real Clear Politics average has Bloomberg ahead by 13 points. That gap might narrow. In 2005, as many city politicos recall, Bloomberg only won by 20 points despite leading Fernando Ferrer by 34 points in one of the last polls.

Yet the most dramatic chapter has already taken place. This past weekend, a Thompson volunteer had his dog's leash in one hand and pamphlets in the other. One couple walked by and apologized for not taking a pamphlet. The man said, shrugging, he was again voting for Bloomberg. “You do have a choice,” the Thompson volunteer insisted with a pang of futility.

When polls close Tuesday, the billionaire will owe his mayoralty to the so-called "Bloomberg 29" as much as the city's residents.