Alexandria Ocasio-Cortez and the progressives' delicate truce with centrist Democrats is over, and the battle over the party's future is already heating up

• Divisions between progressive and moderate Democrats have boiled over following unexpected House losses and President-elect Joe Biden's win.
• The public fight over congressional losses is just the first of what will likely be several flashpoints for Democrats in the coming months.
• Democratic operatives across the ideological spectrum told Business Insider that the truce that progressives reached with more-moderate Democrats to unify behind Biden's candidacy was over.

President-elect Joe Biden hadn't yet won the election when Democratic Party divisions spilled into public view.

During a House caucus call on Thursday, centrist Democrats lashed out at their progressive colleagues, arguing that calls for democratic socialism and defunding law enforcement were to blame for the party's shocking loss of at least half a dozen swing-district House seats.

"We need to not ever use the word 'socialist' or 'socialism' ever again ... We lost good members because of that," Rep. Abigail Spanberger, a Virginia Democrat who prevailed in a tough reelection race, said on the call. "If we are classifying Tuesday as a success ... we will get f---ing torn apart in 2022."

After the call was leaked to reporters, Rep. Alexandria Ocasio-Cortez accused her more conservative colleagues of "finger pointing" and failing to take responsibility for their own strategic shortcomings.

"It's irresponsible to pour gasoline on these already very delicate tensions in the party," Ocasio-Cortez told CNN on Sunday. In a Saturday interview with The New York Times, she described some vulnerable Democrats' underinvestment in Facebook ads and other digital efforts as "criminal" and "malpractice."

Read more: 30 top progressives ready to cajole the incoming Biden administration from its left flank

A few more moderate Democrats, including Rep. Conor Lamb, who won a competitive reelection race in western Pennsylvania, and Majority Whip James Clyburn of South Carolina, pushed back.

Democratic operatives across the ideological spectrum told Business Insider that the truce that progressives reached with moderate Democrats to unify behind Biden's candidacy last spring had expired. They said they expected progressives and centrists to continue to butt heads over the House speakership, leadership of the Democratic Congressional Campaign Committee, Biden's Cabinet, and legislative priorities in the new year.

Democratic flashpoints on the horizon

Some on the left have argued that establishment and moderate Democrats should be taking cues from the left and, as Ocasio-Cortez has advocated, taking advantage of the messaging skills they've honed.

Rebecca Katz, a progressive operative and former advisor to New York City Mayor Bill de Blasio, said centrist Democrats failed to deliver anything besides an anti-Trump message. She said the party needed a stronger proactive message on the economy and bringing down healthcare costs.

"You can't blame moderate losses on the left. That's just ridiculous," Katz told Business Insider. "When their incumbents went down in Democratic primaries, they never thought 'What is the left doing that we're not?'"

Ian Russell, a former deputy executive director of the DCCC, said Democratic losses could likely be chalked up to damaging GOP attacks on left-wing talking points and to various tactical shortcomings. He called for an honest postmortem but said it was impossible to diagnose the problems without the relevant data.

"It's not going to be pleasant, but we need to hold ourselves accountable, and we need to be clear-eyed and cold-blooded in our analysis," Russell told Business Insider.

Rep. Cheri Bustos announced on Monday that she would step down as head of the DCCC following the party's poor showing last week. Battles over leadership of the DCCC and discussions over whether House Speaker Nancy Pelosi should serve another term are likely to further divide progressives and moderates.

Basil Smikle, a Democratic political consultant and former executive director of the New York State Democratic Party, predicted that Democrats' first "big test" of intraparty relations would come with the stimulus negotiations. Pelosi and Senate Majority Leader Mitch McConnell have resumed talks over an economic-relief bill, and Democrats would be forced to compromise to pass one during the postelection lame-duck period.

Senate Republicans have been even less willing than the Trump administration to sign off on a multitrillion-dollar relief package.

"It's not likely that Democrats are going to get a lot of what they want," Smikle said. "I would imagine this is a moment that progressives are going to ask for a lot — it's not unwarranted ... but perhaps the speaker and Biden himself, who has articulated that he's going to work across the aisle, may not feel it's the time for it."

There's a consensus that the party will be forced to reunite in 2021 to maintain its majority in the midterms. But left-wing voices outside Washington have urged progressives to be loud in their opposition to moderate Democrats' demands on all fronts.

"I hope the truce, to the extent there was one, is over, and I hope we start firing on all cylinders and firing shots across the bow," Corbin Trent, Ocasio-Cortez's former press secretary, told Business Insider, adding that the centrist Democrats "are as much our enemy."

"They brought us Trump," Trent said. "They'll deliver us Tom Cotton."