Representative Ro Khanna would have written an even bolder congressional budget, but the Californian is satisfied that progressives have put their imprint on the document.

Now, he wants House Democrats to get to work on enacting it. Unfortunately, a handful of centrist members of the party’s caucus are throwing roadblocks in the way. That’s got the usually mild-mannered Californian calling out colleagues who he says are threatening the party’s ability to govern as boldly as the times require.

“Look,” Khanna says, “everyone has to compromise in Congress. I want Medicare for All; that’s not in the bill. I want free public college; that’s not in the bill. I want student-loan forgiveness for working families; that’s not in the bill. Guess what? You know whose bill it is? President Joe Biden. Last I understood, he won election as president. The Democratic Party needs to unify around his agenda to help people, and anyone who votes ‘no’ on this is sabotaging Joe Biden and sabotaging the Democratic Party’s agenda.”

Earlier this month, Senate Democrats voted for the budget resolution that, as the Associated Press explains, “could clear a path for future passage of a $3.5 trillion, 10-year social and environment package.” Now, it’s the House’s turn. Echoing the message of Senate Budget Committee chair Bernie Sanders, Khanna has taken the lead in making an urgent argument that House Democrats must unite in support of the package.

However, ten* centrist Democrats, many of them with corporate ties, have signaled that they may vote against the House resolution required to begin the reconciliation process for the budget. They are demanding a vote on the bipartisan $1 trillion infrastructure bill before taking up the budget proposal. And since dozens of progressive Democrats announced that they wouldn’t vote for the infrastructure bill if the centrists block the budget proposal, Speaker Nancy Pelosi and the chamber’s Democratic leadership have pushed to have both packages voted on together. In the closely divided House, there are fears that centrist obstruction could derail the entire legislative agenda.

Khanna has bluntly argued in appearances on MSNBC and interviews with Capitol reporters that the centrists are taking a dangerously unwise political gambit.

The California Democrat, who was a cochair of Sanders’s 2020 presidential bid and is a prominent member of the Congressional Progressive Caucus, says his party cannot afford to be divided at a point when it is possible to enact a $3.5 trillion budget that is expected to dramatically expand Medicare and Medicaid, make community-college education free, and fund a Climate Corps and initiatives to save the planet.

“The Biden-Sanders budget is our best chance to usher in the beginning of a new progressive era, having significant public investment in health care, education, childcare, and support for our seniors,” Khanna told me. “We need to coalesce around this blueprint and build on it. This is the time when progressives can begin to deliver on our vision which is now being adopted by the Democratic Party.”

That’s an argument similar to the one made by Sanders, who has been managing the budget reconciliation process in the Senate—with an eye toward passing the budget with 50 Democratic votes and a tie-breaking assist from Vice President Kamala Harris. Sanders has worked with the White House and Senate Democrats to craft a measure that the Vermont independent compares to the New Deal initiatives of President Franklin Delano Roosevelt and the Great Society projects of President Lyndon Johnson.

“What we are trying to do is bring forth transformative legislation to deal with the structural crises that have impacted the lives of working people for a long, long time,” says Sanders. “Whether it is child care, whether it’s paid family and medical leave, whether it’s higher education, whether it is housing, whether it’s home health care—we’re an aging population; people would prefer to get their care at home—whether it is expanding Medicare to take care of dental and eyeglasses and hearing aids, what we are trying to do is show people that government is prepared to respond to their needs.”

That’s an opportunity that Democrats can’t afford to miss at a point when Americans are looking to see whether the party is prepared to govern as boldly as is needed in the turbulent moment shaped by the coronavirus pandemic, economic uncertainty, unaddressed inequity, and the climate crisis.

Addressing his “moderate colleagues,” Khanna says, “A vote against the Biden agenda this week is not only a slap in the face to the president. It will obstruct any shot at adopting the policies that define us as Democrats.”

*Update: After House Democrats began negotiations, a tenth moderate joined the group who may vote against the House resolution required to begin the reconciliation process for the budget.