Progressives have been frustrated by the limits of their political capital — feelings that were exacerbated by what unfolded during the Democratic convention and since. Many questioned the decision to give Republican politicians more air time to present their vision for the country than actual members of the party, including stars like New York Rep. Alexandria Ocasio-Cortez.

Liberals lashed out at House Speaker Nancy Pelosi for backing primary challenger Joe Kennedy in his bid to unseat Green New Deal co-sponsor Sen. Ed Markey. They called her move hypocritical after she cracked down last year on consultants who worked with Democratic primary challengers seeking to oust incumbents.

Days later, Ocasio-Cortez endorsed Alex Morse in his bid to take down House Ways and Means Committee chairman Richard Neal — one of her biggest targets this cycle. The two Sept. 1 elections could bolster either faction's mandate in a potential Biden administration.

Other progressives registered their discontent by voting against the official Democratic platform, taking issue with its exclusion of "Medicare for All." The DNC revealed that nearly 1,100 delegates of more than 4,700 total voted against the platform, including Reps. Ro Khanna (D-Calif.) and Rashida Tlaib (D-Mich.).

The dissent underscores that health care will be a major front in the battle between moderates and progressives if Biden wins. And while it doesn’t compare to the party’s heated 2016 primary, it's plain that bitterness toward the DNC still lingers on the left.

“We're taking steps and it's not the perfect union at the moment, but that's why I keep on telling progressive advocates and activists that we need more progressive activists inside the party operations,” said Jane Kleeb, chair of the Nebraska Democratic Party. “It can't just be every four years creating a petition.”

Kleeb said she was encouraged that Biden and vice presidential nominee Kamala Harris have both gone on the record in opposition to the Keystone XL pipeline. And others on the left are optimistic about what a Biden administration would portend for the movement. Once small in numbers, the progressive wing has expanded its reach in Congress and aims to use it to shape policy if the Democratic nominee prevails.

Some Democrats argue that Biden could be an ideal mediator between the two sides as the Democratic establishment finds itself staring down an ascendant left. Instead of stymieing them, some progressives think he could end up repackaging progressive policies as palatable solutions on issues ranging from climate change to police reform.

“Joe has a long history of being quite moderate,” Andrew Yang, the former populist presidential candidate, said in an interview. So “when Joe decides to embrace or champion a position, he drags the entire center with him.”

Yang said he thinks any policy rifts between centrists and progressives are “overblown.” The multiple crises facing the country, he said, will make big policy prescriptions “reasonable” when in the past they would have been “unrealistic.”

Biden's climate plan, for instance, would have been seen as far too liberal for the party's nominee to embrace five years ago, said liberal Sen. Brian Schatz (D-Hawaii).

"The most impressive political feat, when you look at this climate plan, is to lay down a marker that is no doubt the most ambitious of any major party nominee and not freak anyone out,” Schatz said. He added of Biden, "He's in a position to be a consequential president precisely because his movement, or our movement, covers the ideological waterfront, and it includes everybody from AOC to Colin Powell."

Tlaib pointed to other pressures that the left can apply on establishment Democrats. If they stall on police brutality, protests will make it impossible for Washington to ignore progressives, she said.

“These are people that are out in the streets marching for Black Lives Matter, and now they're freaking United States Congress members,” Tlaib said in an interview, referring to Democrats Cori Bush and Jamaal Bowman, who defeated longtime Democratic House members in primaries this year in St. Louis and New York City.

Bush, who has already had meetings and phone calls with members of the freshmen progressive group known as the “Squad,” said Democrats aren’t meeting the moment on racial injustice and that's why she won. Most lawmakers, Bush added, can’t speak to the movement or understand it the way she can as a longtime Black Lives Matter activist.

“We can give them as many letters, send them as many emails, have them watch as many videos as we can, but they still have a particular perspective,” Bush said in an interview. “So they have theirs and I'm walking in with mine.”

Progressives are also looking to influence a potential Biden administration by continuing to challenge Democratic incumbents in Congress from the left.

If Morse wins, progressives think that they might have a better shot at passing their favored tax policy, since Neal is chairman of the powerful House Ways and Means Committee.

“We’re seeing a number of upsets in Democratic primaries and more establishment types getting replaced with progressive-minded grassroots challengers,” said Mondaire Jones, a Bernie Sanders-endorsed Democrat who won an open New York primary this year. “The best way to inoculate yourself from a progressive primary challenge is to vote in the best interests of the American people.”

A Morse victory would also mean the Squad would double in size next year, giving progressives more leverage in the House. In addition to health care, they see a climate change-focused jobs plan as another issue that could split the party.

“In the House, there are enough progressives that have real weight to force the Biden administration to incorporate progressive demands,” said Max Berger, a former aide to Elizabeth Warren’s presidential campaign. “If the first fight is green stimulus and green jobs, I think progressives will be largely for it. But they’ll also want to make sure it’s big enough, equitable enough to really accomplish our goals.”

Many progressives see the DNC as a barrier to their goals. They were angered recently when, they said, it removed language from the party platform after it was finalized that would have called for ending fossil fuel subsidies and tax breaks. The DNC said the Biden and Sanders campaigns both OKed its removal beforehand.

The left also blasted the DNC for failing to release the vote tally for the party platform until after the convention ended. Progressives said the DNC was trying to bury the news and that the tally should have been included in the platform committee’s report submitted to the convention.

“It just leaves a very bad taste in the mouth, and there’s been no explanation,” said Norman Solomon, co-founder of the liberal group RootsAction.org, of the DNC’s delay. "It’s harder to win over skeptics when we have this kind of behavior.”

A party official said the DNC disclosed the numbers “once we received the final tallies from the states and they were ready to go and finalized.”

Still, many liberals are heartened by the size of Biden’s climate plan. Leah Hunt-Hendrix, co-founder of the progressive donor network Way to Win, said Biden might embrace more left-wing ideas in response to the pandemic and widespread unemployment.

Biden’s climate plan “took a lot of input from the Sunrise Movement and Green New Deal. That shows a lot of progress,” she said. “I think Joe Biden may end up being one of the most progressive presidents. FDR wasn’t all that progressive until he was in that moment in World War II and the Great Depression and needed to create a New Deal.”