Some of the city’s most established pols are on the defensive as younger, more liberal challengers accuse them of letting down Democratic voters in the age of Trump and AOC.

Reps. Yvette Clarke (Brooklyn), Eliot Engel (Bronx/Westchester), Carolyn Maloney (Manhattan) and Jerry Nadler (Manhattan/Brooklyn) are facing potentially serious contests for the first time in years. Reps. Hakeem Jeffries (Brooklyn/Queens), Gregory Meeks (Brooklyn) and Tom Suozzi (Queens/Long Island) have been put on notice, too.

“It’s open season on incumbents and the longer you have served in public life, the more you are a target,” said Doug Muzzio, a political scientist at Baruch College.

A diverse and eclectic cadre of candidates is hoping to ride the momentum from Rep. Alexandria Ocasio-Cortez’s stunning 2018 defeat of 10-term Congressman and Dem Party boss Joe Crowley.

None of the challengers have held elected office before. All use language that sounds by turns idealistic and indignant, cuing off AOC and Reps. Ilhan Omar (D-Minn.), Ayanna Pressley (D-Mass.) and Rashida Talib (D-Mich.). Most of the challengers identify as democratic socialists — leftists who tend to champion big government and take a skeptical view of capitalism.

“We as a society are going to come to a reckoning,” Erica Vladimer, a lawyer who is challenging Maloney, told The Post. “It’s a new generation of women who are leading those conversations.”

Vladimer made headlines in 2018 when she accused former state Sen. Jeff Klein of forcibly kissing her when he was still one of the most powerful men in Albany. (Klein, now a lobbyist, denied the allegation.) She went on to lead the Sexual Harassment Working Group, which successfully pushed the state Legislature to pass a slate of reforms in the spring.

Vladimer, 32, said she would bring the same mentality to Congress, accusing Maloney and House Speaker Nancy Pelosi of going easy on President Trump. Vladimer vowed to “[raise] hell when our president is an alleged rapist and our elected leaders are saying they don’t have time to think about those things.”

Engel, 72, Maloney, 73, and Nadler, 72, have mostly followed the tenuous party line set by Pelosi, who has struggled to contain Congress’ liberal insurgents and shied away from holding impeachment hearings.

The trio still enjoys the advantages of long-term incumbency, like national name recognition and huge war chests. Engel, Maloney and Nadler had $182,283, $340,749 and $638,565 cash on hand, respectively, as of March 31, according to Federal Election Commission filings.

“Competition is good, and a strong sign of the activism and energy that’s working to achieve the goals of the Democratic Party right now,” Maloney said in a statement to The Post.

Her campaign noted that Maloney, whose district includes parts of Brooklyn and Queens, called for impeachment hearings at a rally in Foley Square last month.

Nadler and Engel could not be reached for comment.

But the incumbents will have to adopt new strategies if they want to keep their seats, said longtime political strategist Hank Sheinkopf.

“They’re going to be more aggressively fundraising but they’re also going to be more aggressive in social media, less mail-dependent and less TV-dependent,” he said. “The new world is the world of bodies on the street and fingers on the keyboard.”

Sheinkopf noted the old political machines in Manhattan and Brooklyn have largely disintegrated.

But in the Bronx, where a handful of kingmakers still reigns, Engel’s challenger Jamaal Bowman is making the ruling clique nervous.

“It’s really shaking the party up, especially after the Crowley fiasco,” said a veteran Bronx political observer.

In a phone interview, Bowman cited a litany of liberal proposals he shares with the other newcomers, like support of the Green New Deal and Medicare for all. Unlike some of his peers, he was undecided about decriminalizing sex work, an issue that has gained national notice since AOC-backed Tiffany Cabán made it a centerpiece of her recent campaign for Queens district attorney.

Bowman — who has the backing of the Justice Democrats group that endorsed AOC — is challenging Engel’s prominent support of Israel.

“I think it’s important for us to stand with Israel in terms of ensuring that the Jewish people are not harmed in any way,” Bowman, 43, told The Post. “At the same time, we have to hold the Israeli government accountable for hard-right policies that have led to the humanitarian crisis in Gaza and the Palestinian people.”

AOC is yet to endorse any of the newcomers, whose ranks include Lindsey Boylan, 35, who’s challenging Nadler; Clarke challenger Isiah James, 32; and Meeks challenger Shaniyat Chowdhury, 27.

“As the races shape up, the challengers will absolutely find ways to be allies,” said Boylan, a former Empire State Development official.