Nancy Pelosi’s historic installation as Speaker for a second time and the formal Democratic takeover of the House of Representatives brought a wave of good feelings over the House, no doubt helped by the wonder new members feel taking in the oath, and the avalanche of children and grandchildren (and Tony Bennett!) packing the chamber.

Democratic enthusiasm, fueled by the chance to hold the Trump administration’s feet to the fire, is real, but it may be short-lived. The road map for potential internal dysfunction within the Democratic conference may come from how the House of Representatives behaved in the mirror opposite situation, from 2011 to 2015, when Republicans controlled only the House. And if the House Republicans’ history shows us what is to be avoided, it may come down to one word: “Fight.”

For two-and-a-half years, working for then-House Majority Leader Eric Cantor, I saw this dynamic up close on a nearly daily basis.

“We need to stand up and fight!” a member would urge his colleagues, on the issue of the day—the Bush tax cut expiration of 2012, the government shutdown of 2013, and certainly immigration.

It always sounded good on the surface. But each and every time, it became clear that no matter how Rocky Balboa-esque the imagery was, the call to fight the Obama administration came without a plan to land a punch, win a round, or knock down the opponent. The tactic of simply throwing punches in the air was enough for some members—for enough members to thwart a bill or even the rule to move the bill forward. Essentially, enough to prevent us from getting to 218.

Over-the-top calls to fight created unreasonable expectations of what “one-half of one-third of the government,” as former Speaker John Boehner sometimes called the House, could do. These would typically come from members pushing ideology over solutions (the “Nothing is Ever Good Enough Caucus”) or members simply scared of their own shadows (the “Vote No, Hope Yes” Caucus). Outside groups exploited these divisions, raising a lot money in the process.

So House Republican leadership essentially played pendulum politics, swinging back and forth between the Freedom Caucus and the moderate Tuesday Group to form some kind of a plan that would work. Just as often, we failed, as during the 2012 Bush tax cut expiration, when a leadership member told his colleagues, “I can’t vote yes this week, but I can next week,” or in the lead-up to the 2013 shutdown, when some Republican House members rallied behind Senate Republicans instead of the House colleagues, causing a nasty showdown on the House floor. Time and again, we were unable to get to 218 votes, a majority in the House, on our own. “Getting to 218” became shorthand for our latest woe.

All of which sprang from the constant call to “fight” above all else. It usually led to losing more leverage to the White House and Democratic Senate than one-half of one-third can afford to lose.

Which is precisely where Speaker Pelosi and House Democratic leadership may find themselves.

Democrats are spoiling to fight on multiple fronts. House committees now led by Democrats are eager to investigate every dark corner of the administration, with members already calling for impeachment its leadership does not want.

But House Democrats are facing many divides—generationally, racially, and, ideologically—as the party is being pulled more to the left; infighting is not just inevitable, it has already begun.

“ House Democrats now have their own Freedom Caucus. ”

One need look no further than Democratic freshman sensation Alexandria Ocasio-Cortez, who voted against the rule package for the House—a direct strike at her party’s leadership. Members rarely vote against the opening rule package, but once they have done so, the next logical step is voting against House rules to proceed on individual bills, essentially holding a bill hostage until certain demands, which may or may not have anything to do with that particular bill, are met. Even a threat of voting against the rule could cause leadership problems. In the case of Republicans, it’s why we often resembled Cleavon Little as Sheriff Bart in Blazing Saddles, pulling out a gun and taking ourselves hostage.

Most significantly, Ocasio-Cortez and her freshman colleague Rashida Tlaib announced they would recruit candidates to primary Democratic colleagues, presumably for not fighting enough. Primaries, by definition, pit party members against each other. If Ocasio-Cortez and Tlaib go down this road, they threaten to tear their party apart in the same way some Republicans made the word “establishment” the worst thing an incumbent could be called. (On the night she was sworn in, Tlaib upped the fighting ante by saying about President Trump, “We’re gonna impeach the motherfucker.”)

Taking the gavel in the midst of a shutdown may be a short-term boon for Pelosi, allowing her to begin her tenure by showing she is the scrappy street fighter the conference will demand. Ultimately, though, Pelosi will have to govern. Enacting any of the proposals she laid out in her speech from the speaker’s chair will require compromise.

House Democrats now have their own Freedom Caucus. And that caucus—this new freshman class, and other members of the House who view their role first and foremost as “RESIST”—are not interested in compromise. They want to fight.

It was just over two years ago that Democrats tried to ride a “Fight Song” into the White House. If House Democrats are not careful—and do not learn from the experiences of the former Republican majority—it may begin their own unraveling.