A politically connected law firm that was a big winner in the city’s decision to reform stop-and-frisk policies is leading the charge to fund Mayor Bill de Blasio’s long-shot bid for the White House.

At least 52 employees from the powerhouse firm of Paul, Weiss, Rifkind, Wharton & Garrison combined to give at least $46,250 to de Blasio’s presidential campaign, according to Federal Election Commission filings.

It’s the most financial support Hizzoner has received from any company or group.

In all, de Blasio’s nearly $1.1 million war chest includes at least $134,300 from donors who listed working for law firms.

George Arzt, a longtime Manhattan-based Democratic political consultant, told The Post he believes “the only way 52 members of the firm give money is if they [were] told by someone [up] high to donate — and that would be Brad Karp.”

Arzt is referring Paul Weiss’ chairman, who was a member of a de Blasio-appointed “host committee” that failed in a bid to bring the 2016 Democratic National Convention to Brooklyn, and is a longtime ally of the mayor.

Hizzoner, meanwhile, has appointed some of the firm’s lawyers to the Rent Guidelines Board and Department of Investigation.

But Paul Weiss’ biggest score under de Blasio came in the courtroom.

In 2015, lawyers of the firm received $2.95 million of a $3.24 million settlement after de Blasio opted to settle a 5-year-old federal lawsuit that ultimately required the NYPD to change how police patrol public housing complexes, including reforming its stop-and-frisk practices.

The company’s clients, who claimed they were illegally searched and arrested, were left to split the remaining $295,000.

Paul Weiss – whose eclectic clientele also includes Citigroup, the National Football League and detainees of the US government at Guantanamo Bay – is headquartered in Midtown, and starting salary for first-year associates is at least $190,000.

The company is well known for issuing the 2015 investigative report for the NFL in the “Deflategate” controversy surrounding the New England Patriots.

Its staffers have a longtime history of shelling out plenty of cash to candidates running for federal offices, including $2.8 million last year alone, according to OpenSecrets.org.

Although Karp wasn’t among the 52 company employees who donated to de Blasio, his wife, Roberta, did give $1,000, records show.

Lawyers from other firms who donated to de Blasio include Frank Carone, the crony lawyer for the Brooklyn Democratic Party.

Both he and his wife gave $2,800 each – as did four other members of his law firm, Abrams Fensterman.

Carone represented developers Stuart and Jay Podolsky in a controversial real estate deal with the city that netted the brothers $30 million above the appraised price for 17 buildings in the Bronx and Brooklyn.

City Comptroller Scott Stringer is probing the transaction.

Messages left with the Karps and Paul Weiss were not returned.

Jaclyn Rothenberg, a spokeswoman for de Blasio’s campaign, said “no government decision has ever or will ever be influenced by a donation.”

“We’re thrilled that so many people who care deeply about the success of our city are showing confidence in the mayor’s leadership to be commander in chief,” she added.