In the inside-baseball struggle to be the next chairman of the Democratic National Committee, Minnesota Rep. Keith Ellison and his biggest supporter, Vermont Sen. Bernie Sanders, are sending conflicting signals.

Ellison has made his campaign all about uniting the party, while Sanders keeps highlighting the divide exposed during his presidential primary against Hillary Clinton last year. That more confrontational approach risks undermining Ellison’s message and turning off the Democratic insiders who sit on the DNC, which will elect its next leader later this month.

Powerful surrogates sometimes come with their own agendas and the discordance was obvious Wednesday after former Vice President Joe Biden endorsed Ellison’s main rival, Labor Sec. Tom Perez.

Ellison himself had nothing but nice things to say about the development.

“I admire and respect Vice-President Biden. He has given great service to our country as a U.S. Senator and in the White House,” the congressman said in a statement. “Vice-President Biden is known for loyalty to people he has worked with, and I can certainly appreciate him wanting to support Tom, who worked in the Administration.”

But Sanders cast the endorsement as evidence that Perez is part of “a failed status-quo” that needs to be swept aside.

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"Joe Biden is a friend of mine and I have a lot of respect for Tom Perez. In terms of the next chair of the DNC, however, the question is simple: Do we stay with a failed status-quo approach or do we go forward with a fundamental restructuring of the Democratic Party? I say we go forward and create a grassroots party which speaks for working people and is prepared to stand up to the top 1 percent. That’s why we have to support Keith Ellison,” Sanders said in a statement.

There’s no doubt that Biden’s endorsement further cements Perez’ status as the choice of the party’s establishment (though Senate Minority leader Chuck Schumer, the top democrat in Washington, has endorsed Ellison). And it did not come as much of surprise because people close to former President Obama had so clearly telegraphed support for his former cabinet official.

Related: Tom Perez Enters Race for DNC Chair, Setting Up Test for Obama, Progressives

But Ellison has gone to lengths to try to reassure establishment Democrats that he’s not just a mini-Bernie Sanders intent on tearing their party down. He’s highlighted endorsements from former Clinton allies, batted away talk of a Sanders-Clinton proxy war, noted he’s the only DNC Chair candidate who supported both Sanders and Clinton, and made “unity” his mantra.

"We need to unify, no matter who we supported in the primary," he said during the party’s first official candidate forum in Phoenix.

Ellison has clearly concluded that that is the strategy that will help him win the votes he needs among the 447 members of the DNC, only some of whom are outspoken Sanders allies.

But where Ellison says the DNC needs to be fixed — "Even a good car needs a tune-up sometimes," he said last month — Sanders called for something closer to a trade-in. "I think we need a fundamental transformation of the Democratic Party," he said in December.

Some Democrats have chafed not just at Sanders' message, but the messenger, since the senator is still not technically a Democrat, but an independent, and many Clinton allies think he damaged her in the general election last year by undermining his supporters' faith in the process.

Some of Sanders' closest allies too have reinforced the intraparty split that Ellison and others have tried to smooth over.

"Tom is likely to talk about a broader message and unity, but we all know that the White House staff and others in the Party that are supporting him are doing so to keep control and oppose real change," Larry Cohen, the president of Our Revolution, a group Sanders founded, wrote in an op-ed when Perez announced.

There’s plenty of frustration in all segments of the party about its status quo. But Sanders' statement on Wednesday particularly annoyed some Democrats because it implicated Biden.

While former President Obama is almost universally viewed as a neglectful party leader, the former vice president earned favor among the kinds of people who sit on the DNC by demonstrating more commitment to party building.

Sanders has clearly contributed an enormous amount to Ellison, who was the second congressman to endorse the former presidential candidate in last year’s primary. But the association may have downsides too.