WASHINGTON There is nothing President Donald Trump loves more than winning. On May 24, surrounded by some of the most conservative Republicans in Congress, he savored the second major legislative victory of his presidency by signing into a law a bill that rolls back a host of bank regulations adopted after the 2008 financial crisis.

By liberating small banks from excessive bureaucracy and thats what it was, bureaucracy we are unleashing the economic potential of our people, Trump declared, as Fox News favorites like Sen. Pat Toomey (R-Pa.) and Rep. Sean Duffy (R-Wis.) smiled for the cameras. Grinning alongside them was Sen. Heidi Heitkamp (D-N.D.), who earned a prominent spot next to the president for helping organize the Democratic votes needed to get the bill through Congress.

Up for re-election this fall in deep-red North Dakota, Heitkamp is one of only a few sitting Democrats who believe a photo op with Trump will boost her prospects in November. Joining her and the GOP in supporting the bill were 16 other Senate Democrats, several of whom are also up for re-election this year in states Trump won. To judge by the flurry of enthusiastic press releases issued by the bills supporters, Washington was experiencing a rare moment of bipartisan comity.

But behind the signing-day smiles was the most bruising intraparty fight in recent memory one that has left Democrats of every ideological stripe fuming as the party struggles to renegotiate its rules of fair play in the Trump era.

The anger and frustration has lasted, said one Senate Democratic aide. It has not subsided.

After spending 18 months lambasting the president for showering money on the superrich and pursuing a racist agenda, more than a third of the Democratic Senate caucus voted for a bill that will swell the fortunes of bank shareholders and executives as it weakens protections for consumers and could allow for more racial discrimination in the housing market.

HuffPost spoke with more than a dozen Democratic senators, aides and advocates about what happened behind the scenes as the bill made its way to Trumps desk. Most requested anonymity in order to speak candidly about an emotionally charged battle between friends and allies.

The inflamed tempers dont really have all that much to do with financial policy. Theyre concerned with much more sensitive Washington intangibles the unspoken etiquette that binds lawmakers into coalitions and the way politicians navigate the difference between compromise and corruption. The 2016 presidential election showed Democrats that its old rules were obsolete. But if the bank bill fight is any indication, theyre still figuring out a new way of doing business.

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