Thomas Perez speaks in Birmingham, Ala., on Aug. 21, 2012. (Jay Reeves/Associated Press)

Former vice president Joe Biden has endorsed former secretary of labor Thomas Perez in the race to run the Democratic National Committee, the highest-profile support yet for a candidate seen to be edging ahead.

“With Tom, it’s personal, as it’s always been for me,” Biden said in a statement shared by Perez’s campaign. “Tom knows how to talk to people, not down to them. He knows how to explain why our party’s core beliefs matter to the immigrant family in Arizona and the coal miner in West Virginia. That matters.”

Perez, who entered the DNC race six weeks ago, has released several endorsements from Obama administration veterans, labor unions and Democratic elected officials. The Biden endorsement, which was in the works since Perez’s last days at Labor, does not actually add to Perez’s vote total — only the 447 members of the Democratic National Committee vote on the chair.

But Biden’s willingness to elbow in was significant, because Rep. Keith Ellison (D-Minn.), one of the first announced candidates, is seen to be struggling to gain ground. Ellison was endorsed from the get-go by Senate Minority Leader Charles E. Schumer (D-N.Y.) and Sen. Bernie Sanders (I-Vt.), after Sanders had spent months urging Ellison to run.

At the same time, Democrats like Biden had been encouraging Perez to run; Biden told the New York Times in November 2016 that he would “remain deeply involved in helping shape the direction of the Democratic Party moving forward.” Initially, the impression that the party’s establishment was muscling aside Sanders’s pick rankled left-wing activists. And today, Sanders responded to the Biden endorsement with a familiar criticism of the DNC.

“Do we stay with a failed status-quo approach or do we go forward with a fundamental restructuring of the Democratic Party?” Sanders asked. “I say we go forward and create a grassroots party which speaks for working people.”

As a candidate, however, Perez has touted his own credentials as a progressive inside the Obama administration and refused to criticize Ellison. At a forum last month in Washington, he joined the rest of the leading DNC candidates in saying Democratic donor Haim Saban should apologize for calling Ellison, a Muslim, an “anti-Semite.”

In a statement, Ellison said that Biden is “known for loyalty to people he has worked with,” and he could “certainly appreciate him wanting to support Tom,” but that he was winning over rank-and-file Democrats.

“Democrats in every community tell me that winning elections is the number-one job of the next DNC chair,” Ellison said. “I have won 16 primaries and general elections. They want a DNC chair who has a track record of helping Democrats win elections up and down the ballot, which I have.”

Unlike the last contested DNC race, in 2005, this year’s contest has not seen a front-runner emerge or weaker candidates drop out. Based on private whip counts, Perez and Ellison are seen as having the most support; Pete Buttigieg, the mayor of South Bend, Ind., is seen as close behind. No candidate is seen as having the 224 votes needed to win outright.

Four more candidates have appeared in several forums, and three fringe candidates have asked to be included in the party’s “future forums,” the next of which will happen Saturday afternoon in Detroit. (Vincent Tolliver, a fringe candidate who participated in last weekend’s DNC forum in Houston, has been expelled from the race after emailing the Hill negative comments about Ellison’s religion.) The election for chair will be held Feb. 25 in Atlanta.