Lori Lightfoot will become Chicago’s first openly gay mayor — and the first African-American woman ever to serve as chief executive — after cruising to a landslide victory on Tuesday that transcends the city’s tribal politics.

The political newcomer clobbered the Cook County Democratic chairman by more than 47 percentage points.

With 98.7 percent of the precincts reporting, Lightfoot had 73.7 percent of the vote to Toni Preckwinkle’s 26.3 percent.

“I feel very humbled and honored. I’m gonna do everything I can to earn it,” Lightfoot, 56, told the Chicago Sun-Times from her victory suite.

“We were hoping, based on our polling, that we would do really well. But, this is amazing. More than I ever dreamed of. People really wanted change. They were very troubled by the negative tone of the Preckwinkle campaign. Now, people have new hope for a new beginning.”

The results were so lopsided the Associated Press declared Lightfoot the winner less than an hour after the polls closed.

Over an hour later, Preckwinkle called to congratulate Lightfoot, then conceded the race to a roomful of disappointed supporters chanting her name.

“This may not be the outcome we wanted. But, while I may be disappointed, I’m not disheartened. For one thing, this is clearly an historic night,” Preckwinkle said.

“Not long ago, two African-American women vying for this position would have been unthinkable. And while it may be true that we took different paths to get here, tonight is about the path forward.”

Minutes later, a beaming Lightfoot took the stage in a jam-packed ballroom at the Chicago Hilton and Towers. She called her victory in all 50 wards a “mandate for change.”

Lightfoot’s landslide rivals former Mayor Richard M. Daley’s 2003 re-election bid, when the 14-year incumbent beat the Rev. Paul Jakes Jr., 78.46 percent to 14.02 percent. Patricia McAllister drew 5.9 in that contest and Joseph McAfee 1.62 percent.

“We can and we will build trust between our people and our brave police officers so that the communities and police trust each other–not fear each other,” Lightfoot told her supporters.

“We can and we will break this city’s endless cycle of corruption. And never again — never, ever — allow politicians to profit from elected positions.”

The turnout this year was expected to be a record-low 32 percent. That’s down from 35 percent on Feb. 26 and 41 percent for the 2015 runoff between Rahm Emanuel and Jesus “Chuy” Garcia.

The low turnout should have favored the 72-year-old Preckwinkle. She’s the party boss and the candidate of the black political establishment. Her support from the Service Employees International Union and the Chicago Teachers Union gave her the ground game to bring her voters to the polls.

But, not this time.

“She’s the chair of the Cook County Democratic Party, president of the Cook County Board … That winds up looking like a demerit,” said CTU President Jesse Sharkey.

Lightfoot won majorities of the white, black and Hispanic votes, at least temporarily resurrecting the rainbow coalition that made Harold Washington Chicago’s first African-American mayor in 1983.

Even though 65 percent of Chicago’s 1.6 million registered voters chose to stay home, it’s still a mandate that could strengthen the new mayor’s hand with a City Council that has taken a sharp turn to the left. Aldermen who represent wards that Lightfoot won will at least have to be “respectful of her agenda,” said a veteran political strategist who asked to remain anonymous.

With time running out, Preckwinkle supporters tried to fan the flames of racial politics.

Congressman Bobby Rush warned that the “blood of the next young black man or black woman” killed by police would be on the hands of Lightfoot supporters if the former police board president is elected mayor.

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The attack fell flat. So did the homophobic fliers plastered on car windshields outside black churches.

Those desperation tactics came after Preckwinkle tried and failed to convince former President Barack Obama to get off the sidelines and endorse her. She also pulled her television commercials for much of the campaign’s home-stretch having lost the final month fundraising sweepstakes to Lightfoot by a 2-to-1 margin.

“After Toni went dark, it was pretty much a death march,” said a Preckwinkle supporter, who asked to remain anonymous.

Preckwinkle managed to get back on the air with six days to go with another attack ad.

But, it only served to increase the animosity between two strong-willed black women, who now will operate out of fifth floor offices on opposite sides of City Hall and the County Building–with a political deep freeze inbetween.

Never mind that both women signed a pledge to appear at a unity news conference on Wednesday morning at the behest of the Rev. Jesse Jackson Sr.

On Feb. 26, Preckwinkle won just six wards, nearly all of them near her Hyde Park base where she served as alderman for 19 years. On Tuesday, Preckwinkle’s base shrunk.

“It’s like the opposite of the Midas Touch. She couldn’t catch a break,” said soon-to-be ousted Ald. Joe Moore (49th), who voted for Preckwinkle.

“People want change. They want people they’ve never heard of before. Toni is gonna be part of the same wave that I was a part of. People are frustrated and they’re not distinguishing between incumbents who’ve done a good job and those who haven’t. They just want new people.”

On Tuesday, Lightfoot acknowledged the history she made by becoming the first black woman and the first openly gay person ever to serve as mayor of Chicago.

“Out there tonight, a lot of little girls and boys are watching … They’re seeing the beginning of something, well, a little bit different. They’re seeing a city reborn, a city where it doesn’t matter what color you are and where it surely doesn’t matter how tall you are,” said Lightfoot, who stands 5 foot, 1 inch tall.

“Where it doesn’t matter who you love just as long as you love with all your heart. In the Chicago we will build together, we will celebrate our differences. We will embrace our uniqueness. And we will make certain that all have every opportunity to succeed.”

The runoff was Lightfoot’s to lose from the moment she came, seemingly out of nowhere to finish first on Feb. 26.

It was the worst possible match-up for Preckwinkle. She might have stood a chance against another member of the political establishment such as Bill Daley or Susana Mendoza.

But, Lightfoot had no such baggage. She successfully portrayed herself as a change agent in a change election dominated by the City Hall corruption scandal that threatens to bring down Chicago’s two most powerful aldermen: former Finance Committee Chairman Edward Burke (14th) and former Zoning Committee Chairman Danny Solis (25th).

Preckwinkle never managed to recover from being dragged into the Burke scandal.

The die was cast on Jan. 3, when Burke was accused of attempted extortion for allegedly shaking down a Burger King franchise owner for legal business and for a $10,000 campaign to Preckwinkle.

“Ed Burke fundamentally changed the race. After that, it was a throw-the-bums-out electorate. The only question was, who was gonna be defined as the anti-establishment candidate,” another Preckwinkle operative said.

“It turned out to be Lori. She spent an entire year holding press conferences blasting City Hall.”

Lightfoot’s pollster Jason McGrath said the Burke scandal resonated because it touched a nerve.

“That didn’t come out of nowhere. Peoples’ frustrations and desire … for somebody who’s got independence from the broken machine — that didn’t spring from the Burger King story. That started months before,” McGrath said.

“The fact that this story broke when it did shined a light on it that might not have happened otherwise. But as to whether that was the necessary pre-requisite for us to surge, I don’t know.”

An already wounded Preckwinkle limped into the runoff with a campaign in disarray, having fired her chief of staff, chief of security and campaign manager.

Her only chance was to try and define Lightfoot before Lightfoot had a chance to define herself.

But the strategy backfired. Preckwinkle never quite managed to make the case for why being a “wealthy corporate lawyer” who defended the nation’s “elites” made Lightfoot unfit to serve as mayor of Chicago.

Lightfoot responded quickly to the charge. She also blew the whistle when Preckwinkle used their first debate to compliment Lightfoot for being openly gay, a not-so-subtle reminder to those who may not know that Lightfoot is a lesbian.

The Chicago Federation of Labor’s decision to remain neutral denied Preckwinkle a chance to consolidate support from the rest of organized labor.

That allowed Lightfoot to win endorsements and lucrative contributions from the trade unions that had bankrolled Mendoza’s campaign and from Mendoza, who captured all but one of Chicago’s Hispanic wards in Round One.

It also freed the Chicago Firefighters Union Local 2 to endorse Lightfoot, along with two Northwest Side aldermen who are former firefighters. That was a signal to white ethnic voters on the Northwest Side to support Lightfoot. Ald. Matt O’Shea (19th) and former mayoral candidate Jerry Joyce did the same for Lightfoot on the Southwest Side.

Lightfoot also benefited immeasurably from Willie Wilson’s endorsement.

On Feb. 26, Wilson won 13 of 18 black wards on the strength of his charitable giving. On Tuesday, Lightfoot won all of those wards on the strength of Wilson’s endorsement.

Wilson’s backing also sent a signal to his older, church-based constituency that “contracts and jobs and schools” were more important than their concerns about the fact that Lightfoot is a lesbian.

The race was so lopsided, Lightfoot spent at least some of her time in the campaign’s final weeks working on the transition.

“We’ve got a lot of really smart people who, I think, would be drawn to the possibility of working in an administration that’s focused on change. Isn’t just gonna do the same old, same old,” she said.

“We’ve been getting a lot of people who say, `Call on me. Call on me.’

An argument can be made that Lightfoot got lucky when Burke was charged with muscling a campaign contribution for Preckwinkle.

But, Lightfoot positioned herself to take advantage of her good fortune.

She made the most of the police reform platform that Emanuel gave her. She refused to be bullied out of the race by Preckwinkle when the county board president looked like a prohibitive favorite.

Now, Lightfoot appears poised to be the mayor-elect with only 48 days to put together a new administration.

Contributing: Lauren FitzPatrick, Rachel Hinton

Watch Lightfoot’s full victory speech here: