This was supposed to be the presidential primary race in which the progressive wing of the Democratic Party put it all together. The left was coming for power, not only moral victories. One popular podcast promised that the party’s moderates would soon “bend the knee,” as working Americans flocked to a left-wing presidential agenda.

But after a disastrous month of electoral drubbings that continued with Tuesday’s primaries in Arizona, Florida and Illinois, it has become clear that the presidential promises of political revolution and big structural change will once again have to wait.

Former Vice President Joe Biden is not just beating liberal rivals, all but vanquishing Sen. Bernie Sanders of Vermont and outlasting Sen. Elizabeth Warren of Massachusetts. His candidacy has poked significant holes in the political strategy of their wing of political thought.

Their big investments in organizing could not overcome his name recognition. They could not reshape the primary electorate, while Biden has surged among more moderate voters in Democratic suburbs. They could not cut into his advantage with black voters. And they could not overcome his electability argument — that he is the best candidate to defeat President Donald Trump — as evidenced by the fact that Biden bested Sanders with many liberal voters in Florida on Tuesday.

Biden is also succeeding even as progressive policies such as single-payer health care, robust action on climate change and student debt cancellation continue to poll high among Democratic voters, drawing majority support in some states.

This disconnect, in which policies are popular but the candidates who advocate them are losing, has frustrated progressive groups. They privately split blame among themselves, the candidates they backed and a Democratic electorate that has prioritized fear of losing to Trump above all other concerns.

Rep. Alexandria Ocasio-Cortez of New York, a leading progressive and a top surrogate for Sanders, said in an interview that her wing of the party needed to learn “political lessons” from this race.

Asked for examples, she said that reaching suburban women and older black voters, groups progressive presidential candidates have struggled to win over, may require different political tactics.

“There’s so much emphasis on making outreach as conflict-based as possible,” Ocasio-Cortez said. “And sometimes I even feel miscast and understood. Because it’s about what tools you use, and conflict is one tool but not the only tool.”

She said candidates did not have to choose between class-first politics and addressing racial inequities, but that they must articulate the interplay between them.

“Intersectionality isn’t about virtue-signaling or wokeness, it’s about how we build a majority in progressive Democratic politics,” she added. “If folks have bad racial justice frames, or gender justice frames, or identity frames, you won’t go anywhere in expanding the party.”

Biden has succeeded even in states where voters have voiced support for progressive proposals. As Biden triumphed in Florida on Tuesday night, more than 70% of the state’s voters interviewed by AP VoteCast, a survey of the American electorate, said they favored replacing private health insurance with a “Medicare for All”-type system, the single-payer health care plan that has been a signature issue of Sanders’ campaign.

Exit polls in Michigan, Mississippi, Missouri and Washington, all of which had primaries last Tuesday, showed that the majority of Democrats in each state backed Medicare for All. Common Dreams, the progressive website, tallied 20 states in a row where voters said they supported Medicare for All over private insurance in exit polls. Still, Biden has cruised to victory in many of them.

Matt Morrison, executive director of the labor organization Working America, said left-wing Democrats told themselves a faulty story — that winning the policy argument was the foremost way to build a political coalition. But doing so also requires building trust with voters, he said, because most Americans “look and ask, ‘Are they going to win over voters that aren’t like me or don’t care about politics?’ ”

“The self-branded progressive wing has to go beyond just the policy that fits the needs of the community,” he added. “Voters see that clearly. They’re making judgments about the whole person.”

There is cause for optimism among some on the left, given that issues that were once considered fringe are now popular.

After months of mocking Biden as a feckless front-runner, many progressives acknowledge he managed to make the most important argument to Democrats: that his perceived ability to beat Trump should be valued over any policy in particular.

And it is not just that Biden is winning, but how Sanders is losing: The Vermont senator has not won a single county in Florida, Michigan, Mississippi or Missouri.

The results are humbling for his allies, who entered the race oozing confidence. When Sanders led the field in fundraising, they boasted of a national movement. When Warren was leading in polls and her policy ideas were dominating the conversation, they gloated that progressives did not have one presidential front-runner, but two.

But early victories by Sanders in New Hampshire and Nevada would soon run into a moderate buzz saw. Black voters in South Carolina embraced Biden, making clear to moderate Democrats across the country that the former vice president was their best hope at the nomination.

What happened next was the stuff of movies, as several of Biden’s former rivals dropped out and endorsed him, consolidating their ideological support, sending a powerful signal to voters across the country and propelling him to victories on Super Tuesday. In a mere 72 hours, he went from wounded candidate seeking a lifeline to front-runner with a delegate lead he is unlikely to surrender.

It is that window of time that has left progressives licking their political wounds.

Sanders has yet to comment on Tuesday’s results, and his campaign manager, Faiz Shakir, said on Wednesday morning that the senator would be “having conversations with supporters to assess his campaign.”

It is a stark contrast to what progressive leaders were saying in May.

“This is what we’re going to test,” Shakir said at the time. “Where are people at?”

Not, evidently, with Sanders.