The New York Times headline on Sunday declared, “Biden Tacks Left,” as the newspaper recounted the fact that “when Biden ventured to the Capitol on Friday to help House Democrats out of their thicket, he had to choose sides. He effectively chose the left.”

That there is a left side for President Joe Biden to choose—clearly defined and prepared to stand its ground—is the real story in this fall’s battle royal over infrastructure bills and Democratic budget priorities.

After three decades of building from obscurity to a position of strength within the House Democratic Caucus in particular and the legislative branch in general, the Congressional Progressive Caucus has become more than a faction. It has the potential to be the defining force in the direction of the 117th Congress and a still-new Democratic administration.

Biden recognizes this, which offers an explanation for why he has embraced the argument of the 96-member caucus that legislation to invest in physical infrastructure and human needs must remain linked. But that’s not the only reason why Biden and party leaders are turning to the CPC as an essential ally.

The president, Senate majority leader Chuck Schumer, and House Speaker Nancy Pelosi are Capitol Hill veterans who value political skills when they see them. And during this fight over the Democratic agenda, the striking skills of CPC chair Pramila Jayapal have come to be broadly recognized—even by those who have not always agreed with the Democrat from Seattle.

The first South Asian American woman in the US House of Representatives, Jayapal in just six years has become one of this country’s most respected defenders of immigrant rights. She arrived with an agenda that anticipated that of the members of the Squad—Alexandria Ocasio-Cortez (D-N.Y.), Ilhan Omar (D-Minn.), Rashida Tlaib (D-Mich.), and Ayanna Pressley (D-Mass.)—who would be elected in 2018, and she has welcomed these new members to an expanded and emboldened CPC. Active in the progressive caucus from the start of her congressional career, as a vice chair and a cochair, Jayapal took over as the sole leader of the organization last December. Since then, she has positioned the caucus as a bulwark against the sort of centrist compromises that tripped up the administrations of Bill Clinton and Barack Obama.

With a clarity that stands in stark contrast to the recalcitrance and dodging of Senators Joe Manchin (D-W.Va) and Kyrsten Sinema (D-Ariz.), as well as corporate-aligned centrists in the House, Jayapal has pushed back against efforts to downsize the Democratic Party’s commitment to achieve transformational change. Asked about Manchin’s proposal to slash the $3.5 trillion budget reconciliation bill to $1.5 trillion, the CPC chair said Sunday, “That’s not going to happen. That’s too small to get our priorities in. It’s going to be somewhere between $1.5 and $3.5, and I think the White House is working on that right now because, remember, what we want to deliver is childcare, paid leave, climate change, [and] housing.”

Jayapal’s approach has excited progressives, such as Ai-jen Poo, the cofounder and executive director of the National Domestic Workers Alliance, who on Saturday thanked Jayapal and the CPC for refusing to give ground in the fight to assure that the $3.5 trillion budget reconciliation bill’s commitments to expanded Medicare, funding for caregiving, paid leave, and free college are not reduced. “As you #HoldTheLine in DC to secure an equitable recovery that leaves no one behind,” she tweeted Friday, “millions of us have your backs.”

Accolades for the CPC chair’s negotiating skills—and for the many television appearances in which she has staked out the progressive position—are coming not just from traditional allies on the left but also from Democratic strategists and veterans of past administrations.

“Jayapal is providing a master class these last few weeks in how to wield power,” Brian Fallon, the national press secretary for Hillary Clinton’s 2016 presidential bid, now serving as executive director for the advocacy group Demand Justice, told The Seattle Times.

Jennifer Palmieri, who served as White House director of communications from 2013 to 2015, noted last week that Jayapal has “emerged as a major and effective force in House”—adding that the CPC chair was the “only House leader to correctly predict how this week’s vote [on the physical infrastructure] would go.” Or, as things turned out, did not go.

Last Thursday, Representative Josh Gottheimer (D-N.J.), a leader of the corporate-aligned “centrist” bloc that has sought to force a vote on the $1.2 trillion bipartisan infrastructure bill before an agreement is reached on the more ambitious social infrastructure bill, declared he was “1,000 percent” certain that the smaller bill would pass before the night was done. Jayapal said that would not happen.

She was right. Pelosi did not bring the measure to a vote because Jayapal and her fellow progressives refused to be rolled.

With the support of enough members of the CPC to prevent passage of the physical infrastructure bill in the closely divided House, Jayapal has kept alive discussions about how to secure the top priorities in the $3.5 trillion reconciliation bill, which was crafted by Senate Budget Committee chair Bernie Sanders (I-Vt.) in cooperation with the Biden White House and Senate majority leader Schumer.

Throughout the fight, Jayapal has delivered two core messages. The first has to do with the responsibility of Democrats to use the power they hold to address economic, social, and racial injustice and to protect the planet. Holding true to the faith that guided her as a human rights activist in Seattle, a state legislator, and a first-time congressional candidate in a spirited 2016 primary fight that laid bare differences in the party, Jayapal has brought both passion and urgency to the current fight.

“Child care can’t wait. Paid leave can’t wait. Health care can’t wait. Climate action can’t wait. Affordable housing can’t wait. A roadmap to citizenship can’t wait,” the CPC chair declared last week. “People across America are counting on us to deliver the Build Back Better Act—and they can’t wait.”

The second involves a deeper argument that it is the progressive caucus that is defending Biden’s agenda, and that of a Democratic Party that won control of the White House and the Congress in 2020. In so doing, she has boldly challenged the media narrative that imagines that Manchin, Sinema, and the House centrists represent the president or the mainstream of the party.

“Let’s be clear,” said Jayapal, “96 percent of Democrats agree on how we deliver the President’s entire Build Back Better agenda. A few conservative Democrats are standing in our way of delivering transformational change to families across America.”

On cable show after cable show, on Capitol Hill, and at the White House, Jayapal keeps driving that point home. She has taken this struggle to heart, and she is signaling that she and the caucus she leads will neither blink nor back down. “The Build Back Better agenda that progressives are fighting for isn’t some fringe wish list. It’s the President’s agenda, the Democratic agenda, and what we promised the American people,” she says. “We’re going to invest in roads and bridges, in child care and education, in paid leave and health care, and in climate action and housing. We can do it all—and we must while we have the chance.”