(Bloomberg) -- House Speaker Nancy Pelosi is known as a master legislator for her ability to hold House Democrats together in even the toughest negotiations. Yet she came up short on a crucial border funding bill this week, forced to back down amid bitter caucus infighting.The episode exposed rifts between the party’s moderate and liberal wings, denting the veneer of unity Pelosi largely maintained for the first six months of the Democratic House majority and her second speakership.While she held different Democratic factions together to negotiate an end to January’s government shutdown and tamped down calls to impeach President Donald Trump, the details of a $4.5 billion funding measure sparked bitter House floor confrontations, hallway blame-shifting and angry tweets among Democrats who felt betrayed by their colleagues.The contentious end to weeks of emotion-filled debate over the best way to help migrants housed in unsafe and in some cases deadly conditions also raises questions about the leverage Democrats will wield in upcoming talks on the debt ceiling, spending limits and Trump’s revised North American trade agreement.Without unified negotiating positions, the party will have a tougher time confronting the Republican Senate and White House.Progressive DemandsAs lawmakers were anxious to catch flights for next week’s recess, the House was stuck with the bipartisan Senate bill that passed 84-8 on Wednesday. Pelosi on Thursday initially backed demands from her progressive members aimed at increasing transparency at migrant holding facilities and eliminating extra funds for the Pentagon and Immigration and Customs Enforcement.Senate Majority Leader Mitch McConnell, a Kentucky Republican, rejected those demands, and moderate Democrats, who will face tough re-election campaigns next year, joined House Republicans to demand a simple vote on the Senate’s bipartisan bill. Pelosi ultimately relented, put the Senate bill on the House floor, and it passed 305-102.More Republicans than Democrats voted for the measure -- a rare occurrence in the Democratic-led House.The bill did get support from more than half of Pelosi’s caucus, but most of the speaker’s own leadership team, including Caucus Chairman Hakeem Jeffries of New York and Vice Chairman Katherine Clark of Massachusetts voted against it.Republicans said Pelosi lost control of the House floor, similar to former Republican Speaker John Boehner facing the House Freedom Caucus rebellion that eventually led him to step down.“I don’t believe I revolted against leadership, I revolted against the fact we were passing a bill that wasn’t going to get to the finish line,” said New Jersey moderate Jeff Van Drew.Democrats maintained that Pelosi’s hold on power remains strong, accusing Senate Democrats of undercutting her by voting for the Senate bill.Pence Promises“Pelosi has a strong grip on the caucus, the Senate abandoned this effort,” said Rosa DeLauro of Connecticut, a close Pelosi ally.Pelosi loyalists said the speaker had tried weeks ago to rally her caucus around a proposal before the Senate effort, but progressives resisted every version of the bill that leadership presented. That meant that the Senate committee acted first, on a bipartisan bill, giving McConnell the upper hand.Pelosi made a last-ditch effort to secure some concessions from the White House, reaching out to Vice President Mike Pence on Thursday. He agreed to a 90-day limit for holding children in “influx” facilities and promised to notify Congress within 24 hours after the death of a child in U.S. custody, according to a person familiar with the conversation.Even with these promises, some progressive Democrats were furious with the reversal and blamed moderates.Wisconsin Representative Mark Pocan, one of the leaders of the Progressive Caucus, likened a bipartisan group of lawmakers, including 23 Democrats, that pressured Pelosi to vote on the Senate bill, to a “Child Abuse Caucus” for giving in on the party’s demands. He told reporters the group was protecting companies running migrant shelters.Pocan was later confronted on the House floor by angry moderates over the tweet.“Child abuse is backing a bill that won’t get the kids the help that they need,” Van Drew said, describing the progressive position.Fellow progressive Pramila Jayapal of Washington State lashed out at Senate Minority Leader Chuck Schumer and his caucus.“Senate Democrats have to wake up and stop voting with Mitch McConnell and allow us to have some leverage so we can actually use our leverage in the House,” she said.Tom Cole of Oklahoma, the top Republican on the Rules Committee, said he hopes Democrats learn the lesson that they need to work with Republicans and stop catering to the left.“It depends on what lessons the Democrats draw out of it,” Cole said in an interview. “When it comes time to actually legislating, you are not going to be able to jam the Republican Senate and Republican White House. This is the first recognition of political reality, and it took a national emergency to get us there.”To contact the reporter on this story: Erik Wasson in Washington at ewasson@bloomberg.netTo contact the editors responsible for this story: Kevin Whitelaw at kwhitelaw@bloomberg.net, Anna Edgerton, John HarneyFor more articles like this, please visit us at bloomberg.com©2019 Bloomberg L.P.