NEW YORK (AP) — Public Advocate Bill de Blasio has been elected mayor of New York, becoming the first Democrat since 1989 to be chosen to lead the nation's largest city.

De Blasio defeated Republican Joe Lhota. De Blasio will succeed Michael Bloomberg, the billionaire who is leaving after 12 years.

De Blasio ran on a liberal, tax-the-rich platform that was sharply at odds with Bloomberg's pro-business, pro-development record.

The casting of ballots Tuesday signaled 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.

De Blasio, who as the city's elected public advocate acts as an official watchdog, had 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.

"I'm calling for fundamental progressive change," de Blasio said Tuesday morning as he voted.

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 has pledged to reach out to New Yorkers who feel left behind by what they believed were Bloomberg policies that centered on Manhattan and ignored the city's other four, less prosperous, boroughs. De Blasio, who 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.