Alexandria Ocasio-Cortez may be putting the heat on Congress, but it’s her chief of staff, Saikat Chakrabarti, who’s dropping the napalm.

In the last three weeks, he’s accused House Speaker Nancy Pelosi of being a weak leader, moderate Dems of being racists, and took heat for a T-shirt glorifying a Nazi-sympathizing Indian nationalist.

“If you put in a gatekeeper who’s an arsonist, what is the message that you are sending?” asked Rabbi Abraham Cooper of the Simon Wiesenthal Center.

One Democratic DC source said the “incredibly polarizing” Harvard grad is “pushing this conflict between Pelosi and AOC.

“He and AOC are looking for enemies, they are looking for fight, they are looking to create controversy,” he said.

“And it’s working. It’s raising money, getting more media, raising stature, increasing email lists, increasing profile.”

On July 6, Chakrabarti tweeted that “Pelosi claims we can’t focus on impeachment because it’s a distraction from kitchen table issues. But I’d challenge you to find voters that can name a single thing House Democrats have done for their kitchen table this year. What is this legislative mastermind doing?

Four days later, Pelosi reprimanded the so-called “squad” of young progressives, including AOC, during a closed-door meeting — demanding they stop airing their grievances via Twitter.

“So, again, you got a complaint? You come and talk to me about it,” Pelosi scolded, according to Politico.

It came less than two weeks after Chakrabarti accused what he called “The New Southern Democrats” of being “hell-bent to do to black and brown people today what the old Southern Democrats did in the 40s.” He deleted the tweet 30 minutes later. He added, though, in a subsequent tweet, that moderate Democrats “still enable a racist system.”

On Thursday, Pelosi told reporters “our members took offense.” On Friday, the spat heated up again with the official Dem account attacking Chakrabarti for “explicitly singling out a Native American woman of color” (Rep. Sharice Davids of Kansas) with his two-week-old tweet. “Who is this guy?” it asked.

The chief of staff replied, “I’m not interested in substance-less Twitter spats,.”

Dem strategist Brad Bannon says Chakrabarti’s behavior is unprecedented — and potentially dangerous for AOC’s career.

“There’s no point in having a staffer criticize another member,” said Bannon. “If AOC wants to, that’s one thing … I’m trying to think of another instance of a staffer going after a member of Congress, and I don’t remember it ever happening before.”

“He’s not a normal chief of staff,” said the Democratic source.

The first Dem source said the grenade-throwing has increased AOC’s visibility, but has sapped her power in the House.

Chakrabarti declined to comment.

Chakrabarti’s tweets are closely scrutinized because he’s not simply AOC’s chief of staff, he’s the architect of her campaign — and the rainmaker. After a cashing out of Silicon Valley (he founded Mockingbird, a web-design tool), Chakrabarti used his newfound money to shepherd AOC’s rocketing career.

But despite his success, he’s made serious missteps.

Last year, during AOC’s campaign, Chakrabarti appeared in a video wearing a T-shirt with the likeness of Subhas Chandra Bose, a radical Indian nationalist and Nazi supporter who lived in Berlin for two years. While in Germany, Adolf Hitler helped Bose assemble an armed force.

“They are creating a situation of a moral blank slate,” said Rabbi Cooper of Chakrabarti’s offensive apparel.

“It’s very dangerous.”

Chakrabarti has not only been dogged by ethical controversies — he’s been immersed in legal ones.

In March, several weeks after Ocasio-Cortez took office, she and Chakrabarti were named in a complaint to the Federal Election Commission that accused them of setting up a $1 million slush fund by diverting money from two campaign committees to shell companies that Chakrabarti controls.

Chakrabarti keeps his personal finances private. Under federal law, congressional employees who earn more than $126,000 a year — the typical salary of a chief of staff — must fill out financial disclosure forms that list their investments and outside income. Chakrabarti gave himself an $80,000-a-year paycheck.

His newfound role as Democratic flamethrower is a surprise to many.

He grew up in Fort Worth, Texas. After earning a degree in computer science in 2007, he worked at Connecticut hedge fund Bridgewater for a year before decamping to San Francisco and delving into the start-up world. He married his college sweetheart, attorney Kamilka Malwatte, who is pregnant and “due very soon,” according to an employee at the couple’s former West Village apartment.

Former San Francisco roommate CJ Messinger, a divorce attorney, says he never expected Chakrabarti to segue into politics — especially among socialist Democrats.

“I was surprised that he’s a liberal,” said Messinger, recalling their political discussions when they lived together in 2010. “He seemed to be very fiscally conservative.”

But a close Harvard friend said it’s no surprise that after Chakrabarti cashed out in the tech arena, he would use his money to “make the world a better place.”

“I think there is a lot of corruption in politics and Saikat is pretty new and he’s not corrupt,” said the Harvard friend. “I think he just wants to do the right thing, even if someone powerful wants to do something else.”