Manhattan Rep. Jerry Nadler announced on Monday he’d back his former aide in the crowded and high-profile race to succeed him in Congress. 

“Since I announced that this term would be my last, people naturally ask who I believe is the best candidate to succeed me,” Nadler said in a video message about the 12th Congressional District race. “As the field has taken shape, one candidate by every measure stands above the rest: Assembly member Micah Lasher.”

“He’s emerged as New York’s protector-in-chief against all things Trump,” the 78-year-old added, “and drafted the blueprint for what Democratic-led states can do to fight back.”

Lasher, who represents the Upper West Side in Albany, began his political career working as a congressional aide for Nadler before ascending to roles in Mayor Michael Bloomberg’s administration and as a policy director for New York Gov. Kathy Hochul.

“Jerry Nadler has set an incredibly high bar for decades for smart, principled, progressive leadership on issue after issue,” the 44-year-old responded in a statement. “I’m honored beyond words to have his support.”

Nadler’s endorsement is crucial for Lasher, with House Speaker emerita Nancy Pelosi (D-Calif.) set to endorse primary rival Jack Schlossberg.

“He’s a nice guy, and he comes from a nice family, but what’s his experience for this job?” Nadler said of Schlossberg, the grandson of former President John F. Kennedy, in an interview with The New York Times. “No, I don’t think people ought to support him. I don’t think they will support him.”

Allen Roskoff, founder and president of the Jim Owles Liberal Democratic LGBT club, said it’s Lasher’s race to lose — but acknowledged Caroline Kennedy “has a lot of chits” in the party who could give her son a boost.

“Lasher is the front-runner. That’s not a secret,” said Roskoff, who resides in the district. “Nadler’s endorsement matters.”

Nadler has a lot of influence with the political clubs on the Upper West Side, who’ve fallen behind Lasher, and “If the election were held today, Lasher would win,” added the LGBT Dem group leader.

Since being elected to the state Assembly, Lasher has introduced legislation to crack down on grocery price hikes and to allow Americans to sue federal immigration agents for violating their civil liberties.

Lasher also backed bills to ban protests outside of religious services and supported pro-Israel positions — before endorsing socialist Zohran Mamdani for mayor.

But the onetime amateur magician recently pulled a disappearing act on his constituents that got him in hot water.

Hours before a winter storm that dumped nearly a foot of snow hit the district, Lasher skipped town for a “solidarity” trip to Minnesota following the fatal Jan. 24 shooting of ICU nurse Alex Pretti by federal border agents.

“They are engaged in a battle, and they want to know that we are on their side. And we are,” he said in a series of videos posted to social media while New Yorkers grappled with the white stuff.

New York City Comptroller Mark Levine, Council Member Gale Brewer, and state Sen. Brian Kavanagh have also endorsed Lasher.

Nadler informed his constituents last September that he would not seek re-election to an 18th term.