What if Democrats had their own Tea Party–esque rebellion? It might sound far-fetched, but it’s less so after this past week. On Thursday, House Democrats revolted against the president, decided to fight a largely unwinnable battle because of their principles, and even stomped their feet a little bit. All of a sudden, a wing of the president’s party appears to be hyperprincipled, unpredictable, and eager to buck leadership. If this is a trend instead of a blip—and some top House Democrats say it’s a trend—then the president may have more in common with House Speaker John Boehner than he realized.

At hand were two provisions added to a last-minute, must-pass government-funding bill that would prevent a shutdown. Democrats were comfortable with the 1,603-page legislation except for two late-breaking provisions: one that would change the Dodd-Frank bank regulation bill, and one that would let donors give more cash to national political parties.

Things started looking tricky for the president when Sen. Elizabeth Warren, a liberal Massachusetts Democrat who’s made battling Wall Street her signature issue, came out vocally against the bill.

Among a powerful sector of Hill Democrats, including House Minority Leader Nancy Pelosi, this consensus emerged: The bill as it stood—with the Dodd-Frank and campaign finance changes—wasn’t just unsupportable, it was immoral. And then, the political bedfellows started to get strange. Those Democrats quickly found themselves on the same side of a contentious vote as Tea Party Republicans (though conservatives’ opposition was largely due to the legislation’s funding of the president’s immigration move). Meanwhile, President Obama and Boehner—both of whom supported the CRomnibus bill that would fund the government, among other things—found themselves staring down unruly caucuses that were willing to ignore their pleas, cast aspersions on their integrity, stand defiantly on populist principles, and vote just like they damn well pleased.

The shift became blatant during a lengthy meeting that House Democrats held in the basement of the Capitol before the vote. The president’s chief of staff, Denis McDonough, swung by the meeting to try to convince attendees to vote for the spending bill despite the provisions they found onerous. He left looking blanched and chagrined (though, to be fair, he might always look like that) and wouldn’t give the reporters who swarmed after him any details on how the meeting went.

But some of the Democrats who trickled out after him were happy to mouth off. When reporters asked Democratic New Jersey Rep. Bill Pascrell if McDonough’s pitch had persuaded many Democrats to change their minds, his response was emphatic.

“Absolutely not.”

Oregon Rep. Peter DeFazio called both provisions of the funding bill “unbelievably odious” and said the chief of staff’s pitch was “somewhat tepidly received.” Then he made a point Democrats would make over and over throughout the night, and one that’s straight from the Tea Party playbook: Democrats need to stand (and, specifically, to vote) on principle, even if those votes are doomed on the Hill, so they can win elections. If they don’t vote their principles on economically populist issues like Wall Street and campaign finance, DeFazio argued, they can expect to see repeats of the 2014 midterms for the indefinite future.

That is not the rhetoric of a group of representatives who feel like they need to compromise and “show they can govern.” That’s the talk of angry backbenchers who feel betrayed by party leadership. Tea Partiers make a parallel argument, charging that Republicans’ repeated nominations of moderates like John McCain and Mitt Romney cost them electoral victories.

Californian Democratic Rep. Jared Huffman was channeling Tea Party energy Thursday night.

“You don’t want to talk to me,” he said when I first approached him as he emerged from the meeting. “I’m just a foot soldier.”

But after being pressed, he said he doubted McDonough’s pitch had much sway.

“I’m walking out of this caucus meeting feeling very proud of my caucus, because there was moral clarity, there was conviction,” he continued. “I had a feeling a few moments ago that we stood for something. I hope it holds.”

Pick an issue like immigration or deficit spending, and a Tea Partier might say the exact same words.

But this revolt wasn’t just unruly backbenchers; outgoing Democratic Congressional Campaign Committee Chairman Steve Israel was also impassioned and unequivocal in his opposition.

“These are core Democratic principles and values,” he said. “That’s why we’re here, and we ought to keep fighting on those values.”

“We’ve got to draw a line in the sand for the middle class and for working families,” he added.

Illinois Rep. Jan Schakowsky, a staunch Pelosi ally, emerged from the meeting excited.

“People were inspired to dig deep and to make very passionate speeches,” she said.

She said that Rep. John Lewis, the Georgia Democrat and civil rights icon, argued passionately for fighting the bill. There was lots of cheering, she said.

“It was kind of like church,” she added.

It wasn’t enough, however. Fifty-seven Democrats voted for the CRomnibus—largely due to the president’s lobbying in its favor—and it passed 219–206. But the revolt still matters. Rep. Elijah Cummings, the ranking member on the House Oversight and Government Reform Committee, said the intra-caucus fight signals that House Democrats will be more assertive on these issues in the future, even if it means bucking the White House. He argued that Democrats struggled to turn out their base voters this cycle because they hadn’t been principled enough.

“People have to feel that you are fighting for them,” he said shortly after the vote.

“Basically you can buy a district, easily, if you’ve got the money,” he continued. “That’s not what the Founding Fathers were all about. So sometimes you just have to stand up and fight. Our constituents want us to fight.”

Invoking the founders, bucking party leadership, and arguing that we’ve got to “stand up and fight”—for Tea Party activists, that will sound extremely familiar.

“I do expect to see, in the future, these kinds of fights,” he concluded. “And I think they’ll be even tougher.”