The casting of ballots Tuesday signals the beginning of New York City’s farewell to Mayor Michael Bloomberg, who has helped shape the nation’s biggest city for 12 years, largely setting aside partisan politics as he led with data-driven beliefs and his vast fortune.

Republican Joe Lhota, a onetime deputy mayor to Rudolph Giuliani, has vowed that he will largely continue Bloomberg’s policies, which have helped make New York one of the nation’s safest and most prosperous big cities, though they also may have contributed to the city’s widening income equality gap.

But while polls show that New Yorkers largely approve of Bloomberg’s record, those same surveys show a hunger for a change in style and tone, which is why Bill de Blasio is poised to become the first Democrat elected mayor in more than a generation.

De Blasio, who as the city’s elected public advocate acts as an official watchdog, has positioned himself as a clean break with the Bloomberg years, promoting a sweeping liberal agenda that includes a tax increase on the wealthy to pay for universal pre-kindergarten and improved police-community relations.

Those tactics, and a pledge to reach out to New Yorkers who feel left behind by what they believed were Bloomberg’s Manhattan-centric policies, have been rewarded in the polls. De Blasio, 52, has been up nearly 40 percentage points in every survey conducted since the general election matchup was set nearly two months ago.

To his supporters, de Blasio symbolizes the city’s progressive possibilities He hails from Brooklyn, is married to an African-American woman and is father to two interracial teenagers, one of whom sports an Afro that became a sensation on the campaign trail. But he is also a consummate pragmatist, having worked for both Bill and Hillary Clinton and Gov. Andrew Cuomo, and was known for closed-door wheeling-and-dealing while serving in the City Council.

He was a distant fourth for much of the summer in the crowded Democratic primary, only to surge past former front-runners including City Council Speaker Christine Quinn and ex-Congressman Anthony Weiner, and is now on the verge of ending an improbable Republican winning streak in the mayor’s office.

Though registered Democrats outnumber their Republican counterparts 6 to 1 across the city, the last Democrat to become mayor was David Dinkins in 1989. However, the GOP victories were tied to some extraordinary events that scrambled the political landscape. Giuliani defeated Dinkins in 1993 amid fears about the city’s soaring crime rates, and Bloomberg won in 2001 largely thanks to his fortune and the fallout from the Sept. 11 attacks.

Lhota, the former head of the Metropolitan Transportation Authority, has pledged to continue their fight, suggesting that de Blasio would handcuff the NYPD by reforming stop-and-frisk, the tactic that allows police to stop anyone deemed suspicious. Stop-and-frisk’s supporters believe it has driven down crime while its critics, including de Blasio, think it is unfairly targets minorities.

But few of Lhota’s arguments have resonated, and he has struggled to raise money. He appeared to score some points in the second of the candidates’ three debates by suggesting that the city would return to its crime-ridden past if de Blasio won, but that did little to slow the down the rushing sense of inevitability that surrounds de Blasio.

At this point, a Lhota victory Tuesday would be regarded as one of most unlikely upsets in the city’s political history.

Polls open at 6 a.m. and close at 9 p.m. Experts do not believe turnout will be high.

(AP)