The mayor flashed the detractors his trademark smile and a thumbs-up.

It may seem counterintuitive that a new mayor who won the Democratic primary by just 7,197 votes — eight-tenths of 1 percent — would so confidently brush off his critics as they are gearing up to challenge him, at a moment in his tenure when many leaders would be looking to broaden their appeal.

But Adams knows political trends are working to his benefit: From President Joe Biden to Mayor Jacob Frey in Minneapolis, centrist candidates have been seizing executive power throughout the Democratic Party, even as far-left lawmakers made recent gains in the New York City Council and the Boston mayor’s race last year. Large cities throughout the country backed pro-police candidates and ballot measures in a seeming rebuke to the “defund” the police movement that had taken hold following the murder of George Floyd in 2020.

In New York, progressives aren’t satisfied with Adams’ law-and-order agenda, but until now they hadn’t figured out how to effectively rebuke him either.

In his own race, Adams’ toughest competitor wound up being a like-minded moderate Democrat, while progressives squandered most of the campaign cycle trying to figure out who to support and treated the ultimate winner with kid gloves. Little money was spent on attack ads against Adams, even as he described a vision for the city that was out of step with the progressive movement — one amplified by millions of dollars in support from hedge fund magnates backing his candidacy.

Adams sees this as his moment and is all but daring the left wing of the party to take him on.

As last Wednesday’s rally showed, his opponents are now getting ready.

“I don’t think it’s a secret that the left has been in disarray,” Zara Nasir, coordinator of “The People’s Plan,” said in an interview. “I’m not trying to hide it. This is an attempt to do something a little bit more coordinated and aligned than things have been.”

“The strategy is to focus on policies and issues,” Nasir added.

To that end, the blueprint her alliance released on Wednesday zeroes in on Adams’ early decision to require budget cuts from nearly every city agency — spending reductions his team insists will not result in any diminished services, and ones they argue were necessary to rein in runaway spending under his more liberal predecessor, Bill de Blasio. (The preliminary budget is still nearly $100 billion.)

“The People’s Plan” paints an entirely different picture.

“Our communities have been devastated in ways that are measurable and unfathomable,” Jawanza James Williams of the activist group VOCAL-NY said as he kicked off the rally. “And Eric Adams’ proposed preliminary budget does not account for our realities, does not account for our nuances.”

The speakers ticked off a series of concerns with the $98.5 billion fiscal plan: Lack of investment in dilapidated public housing, insufficient funds for affordable housing, too much money for charter schools compared to their public counterparts.

The rally took place on the heels of another well-attended protest of Adams’ decision to halt the expansion of its organics recycling program — a priority for environmentally-conscious groups given that one-third of the city’s residential waste comes from compostable food scraps.

Adams also took heat from Democrats of all ideological stripes when he appointed three people with a history of anti-gay remarks to high-ranking city jobs. The pushback was not enough to dissuade him from going forward with the hires but created a public fissure early in his tenure.

In the realm of public safety, where Adams and the left-wing groups are most at odds, the demonstrators slammed his plan to reinstate a police unit that was disbanded for its involvement in controversial shootings. Adams argues that as a Black man who was assaulted by cops before opting to join the department and agitate for change from within, he is uniquely positioned to ensure that the unit reverses crime without unfairly targeting people of color.

“This is my life’s work, dealing with reforming police and public safety,” Adams told ABC’s Bill Ritter in a Jan. 30 interview. “We’re not going backwards. We’re not going to use tactics that are abusive to zero in on those who are carrying guns.”

“I’m not going to have a police department that’s going to illegally and unfairly target Black and brown men in the city like we saw in the past,” he added.

The mayor’s office declined to make Adams available for an interview regarding his relationship with the left.

City Hall Communications Director Maxwell Young said in a statement that the mayor “will continue to work with a broad coalition of partners, and that broad coalition will continue to see their goals reflected in this administration’s plans and accomplishments.”

But Adams, without naming names, has left little room for confusion about how he perceives his critics on the left.

“We can’t fail, and there are too many people who believe we must be safe and we can’t be distracted by the loud noise of the numerical minority that believes we can’t move this agenda forward,” Adams said in the ABC interview.

He outlined several positions that are out of step with the progressive movement: Going after subway fare evaders and shoplifters and people taking shelter on train cars.

“We have to be compassionate, but we have to be clear that laws must be followed,” Adams said.

The mayor, a retired NYPD captain, took to showing up to crime scenes late at night and denouncing those who inflict violence during his first weeks in office. By contrast, “The People’s Plan” lists as one of its guiding principles “resources not criminalization” and notes, “For every criminalized New Yorker there is a social safety net or resource that has failed them.”

One of the biggest public disputes in this realm took place before Adams even assumed office.

After announcing his new Department of Correction commissioner in December, the mayor-elect indicated partial support for the controversial solitary confinement policy at the Rikers Island jail complex.

Opponents in the incoming City Council penned a public letter condemning that position, and Adams bristled at the fairly commonplace political maneuver, suggesting none of them had the right to criticize him.

“I wore a bullet-proof vest for 22 years and protected the people of this city. And when you do that, you have the right to question me on safety and public safety matters,” Adams said at the time.

The exchange served to demonstrate not only the pending showdown between the new mayor and left-leaning Democrats, but his sensitivity to criticism on matters of public safety.

“His response to our letter was pretty aggressive. That’s all I needed to see to recognize what we’re up against,” Shahana Hanif, co-chair of the City Council’s progressive caucus, said in a recent interview.

Hanif, who represents the liberal bastion of Park Slope, Brooklyn, said the caucus so far has 30 members out of a body of 51. She and more than a dozen people interviewed for this story regard it as a vehicle for organized opposition to Adams.

“This caucus is first and foremost the accountability machine to the mayor,” Hanif said.

It remains to be seen whether Council Speaker Adrienne Adams, who backed Eric Adams in the mayor’s race but won her leadership contest without his support, will empower the progressive caucus. (The mayor and the speaker are not related.)

The group was born out of a similar movement in 2009, when Hanif’s predecessor, now-City Comptroller Brad Lander, and former Council Member Melissa Mark-Viverito led the body’s opposition to Mayor Mike Bloomberg, a corporate-minded billionaire and lifelong political party hopper, and Council Speaker Christine Quinn, a Democrat.

At the time, New York City’s progressive wave was cresting.

De Blasio and John Liu, students of the left, had been elected to citywide office — public advocate and comptroller, respectively. The Working Families Party, then the anchor of the operation, had defeated five Council candidates backed by Democratic Party machines and several other incumbents across the city. “Occupy Wall Street” had yet to take shape, but concerns about the lack of affordability — which would serve as the underpinning of de Blasio’s successful mayoral campaign in 2013 — were already forming.

The movement had many architects, notably the late Jon Kest, whose vision is still heralded today by his political disciples as unparalleled. Emma Wolfe, a former labor operative who became de Blasio’s chief of staff in City Hall, maneuvered behind the scenes to scoop up electoral wins while the Working Families Party merged the ideology of activists with the financial resources of unions.

Little of that model remains today.

Following a blood feud between former Gov. Andrew Cuomo and the Working Families Party, the labor organizations opted to leave the political organization rather than suffer Cuomo’s wrath. De Blasio and progressives split over housing and policing issues once he became mayor. Mark-Viverito became Council speaker, rendering the progressive caucus somewhat pointless.

And perhaps most importantly, the left no longer had Bloomberg leading the city and Quinn partnering with him in the Council. No matter the depth of the divide between progressives and de Blasio, he was not a Wall Street defender who had belonged to the Republican Party when it suited him, like his predecessor.

Therein lies the challenge for the left: Convincing an electorate worried about public safety that a crime-conscious mayor who grew up poor, worked his way up to police captain after being beaten by cops as a teen, and won a tough election with widespread union support, is out of sync with Democrats — even if he parties with rich Republicans and calls himself a “compassionate capitalist.”

Several progressive lawmakers have privately acknowledged that challenging Adams’ approach to crime could prove a liability at the polls next year, when the 51 Council members are up for re-election due to redistricting.

Adams’ defenders publicly agree with that sentiment.

“From owing his mayoralty to middle-class non-Manhattanites to his focus on fixing crime against liberal orthodoxies, Eric Adams is the second coming of Ed Koch,” consultant and long-time Bloomberg adviser Stu Loeser said of the city’s 105th mayor who served from 1978 to 1989.

He said Adams’ critics are not aligned in their disagreements with the new mayor, which, he added, “makes it really hard to build a coalition against him. Because most people agree with what he’s doing on most things.”

Former City Council Member David Greenfield, who leads the anti-poverty nonprofit Met Council, said Adams’ political superpower has been his work ethic — particularly in contrast with his predecessor, who was dragged for late-morning jaunts to a Brooklyn gym.

“Every New Yorker respects hard work, regardless of where you are on the political spectrum,” Greenfield said. “That’s how he’s earned the credibility that no single politician on the ‘left’ has.”

“Like any true New Yorker, he’s just not fazed by the nay-sayers,” Greenfield added. “If anything, the left-wing criticism only seems to embolden him — he almost relishes it.”

The progressive groups’ political strategy, for now, seems to be pitching a wide tent that covers everything from recycling to public education to controversial hires — a broad approach that several left-leaning operatives privately warned may become too unwieldy to penetrate the electorate.

What’s more, Adams and other moderates — a descriptor the mayor rejects, as he believes political labels fail to capture his complexities — have made strides in depicting progressives as wealthy white people who bear little connection to the troubles of those they purport to represent.

In response, “The People’s Plan” and the progressive caucus have made diversity a priority.

“Gone are the days when white progressives can be the face of this movement, and I think to good measure,” said Nasir, a Pakistani-American.

Equally important, she said, is expanding progressives’ appeal by conveying a positive vision instead of simply opposing the mayor.

“This is about a long-term vision for New York City. It’s beyond this mayor. It’s beyond the current politics of this city,” Nasir said.

For now, Adams’ re-election is a political lifetime away and will hinge on external factors that have not been determined, like crime trends and pandemic recovery.

But, after being caught flat-footed in 2021, the left is already paying attention to 2025.

“It’s never too soon — as we saw we were not quite prepared for last year,” Working Families Party State Director Sochie Nnaemeka said in an interview. “I don’t know what kind of pool we’re looking at right now, but I’d be surprised if he didn’t have a serious challenge to his left.”

After a brief pause, she added, “We should expect more from this mayor.”