WASHINGTON Days after the November election, the progressive wing of the Democratic Party was ascendant. There was no greater sign of its rising stature than the momentum Rep. Keith Ellison of Minnesota was enjoying in his race to chair the Democratic National Committee .

Ellison, co-chair of the Congressional Progressive Caucus and a supporter of Sen. Bernie Sanders (I-Vt.) during the 2016 presidential primary, was racking up endorsements not only from Sanders and Sen. Elizabeth Warren (D-Mass.), but establishment figures as well, including Senate Minority Leader Chuck Schumer (D-N.Y.) and Randi Weingarten, president of the American Federation of Teachers both of whom backed Hillary Clinton in the primary.

But in December, former Labor Secretary Tom Perez jumped into the DNC race. Now, Ellison and Perez are neck-and-neck , with the election days away. The DNCs 447 voting members will decide the partys next chair in Atlanta on Saturday.

That has some Ellison supporters worried that their chance to reshape the party is in danger of disappearing. In an attempt to head off Perez, some prominent Ellison supporters argue that failing to elect him would squander a major opportunity to energize the progressive grassroots and heal the wounds of the 2016 presidential primary.

Keith Ellison had incredible support from the quote-unquote establishment side of the party, the progressive side of the party, the grassroots and the elected officials. Nobody was clamoring for another entrance, and yet we got one foisted upon us, said Alex Lawson, executive director of Social Security Works, an organization fighting to expand Social Security benefits.

If Tom Perez were to win, the message that would send to the grassroots, to labor unions that endorsed Ellison before Tom Perez joined the race, [is] that their voices, their muscle, their enthusiasm and turnout doesnt matter, Lawson added.

Ellison backers acknowledge that the liberal protest movement that has taken shape since President Donald Trumps inauguration not the DNC race has become the focus of grassroots energy. A loss for Ellison now could limit the partys ability to tap into that enthusiasm, but it wouldnt stop the movement.

If Perez wins, were not gonna come out with pitchforks and say, No, no, no, said Murshed Zaheed, political director of Credo Action, an online progressive heavyweight that has experienced record growth since Trumps inauguration. But people are going to roll their eyes and just keeping doing what they do. Its going to keep the DNC what it is: an irrelevant, old, stale entity that hasnt been re-serviced since the Howard Dean days. (Zaheed noted that he spoke to HuffPost in his personal capacity, since Credo isnt endorsing in the race.)

The role of DNC chair is primarily to raise funds, recruit candidates for office and represent the party to the media. But in the wake of major electoral defeats, the contest to fill the post tends to reflect struggles for power within the party.

By encouraging Ellisons candidacy in November, party leaders appeared to be affirming the post-election analysis of many bitter progressives: that Democrats failure to embrace economic populism and grassroots energy had hurt the party in turning out its base and appealing to white Rust Belt voters who voted for Barack Obama , but opted for Trump in 2016.

It also was an olive branch to Sanders supporters still reeling from a primary race in which they felt that the DNC favored Clinton.

Then, in December, aides to then-President Obama, dissatisfied with Ellison, encouraged then-Labor Secretary Perez to run. His candidacy has since taken off with the blessing of top figures from the Obama White House. Obama himself praised Perez in comments widely interpreted as an endorsement . Former Vice President Joe Biden and former Attorney General Eric Holder threw their support behind Perez this month.

Perez is an unlikely target of progressive opposition, given his strong liberal credentials. He earned widespread praise from unions for turning the Department of Labor , once a minor federal agency, into a powerhouse advocate for workers rights. Prior to that, as head of the Department of Justice civil rights division, Perez led the Obama administrations historic investigations into police abuses.

Indeed, many progressives now backing Ellison would have loved to see Hillary Clinton pick Perez as her running mate , and still hope he will run for governor in 2018 in his home state of Maryland.