After Obama ally Tom Perez won a bitter battle for control of the Democratic National Committee this winter, he vowed to unify both the party’s traditional wing and Bernie Sanders’s ascendant left-wing movement.

Perez is now getting a crucial test of that pledge. Ahead of an upcoming party gathering in Las Vegas, he will announce his nominations to the body of the DNC — as well as his picks for key committee slots in the party that decide crucial party functions.

A list of Perez’s choices, leaked to Vox, shows plenty progressives are sure to celebrate. The new committee includes more union representatives that at any point in the body’s recent history. The number of Native Americans and millennials has doubled, and the DNC added its first DREAMer — Ellie Perez of Arizona. Rep. Keith Ellison (D-MN), the Sanders ally who lost the DNC chair race to Perez, also joins the DNC’s most-powerful body, the executive committee. So does Royce West, a Texas state senator who supported Ellison’s bid for the chair.

But some longtime allies of both Sanders and Ellison argue that the new DNC chair should have done more to include members of the party’s left flank, and in particular criticized the decision to put what they view as allies of the party’s old guard in key positions.

“They’re not accommodating, or even trying to accommodate, the Bernie people,” said James Zogby, a Sanders ally and founder of the Arab American Institute, who was not reappointed by Perez to serve on the DNC’s executive committee. “I don’t want this fight and still don’t want to have a fight, but I’m troubled. This doesn’t look good.”

Other Sanders allies had more measured responses to the list of appointments. “Obviously, I always want more Bernie folks and more leftists on there,” said Melissa Byrne, an activist and former Bernie campaign staffer who ran for DNC vice chair this spring. “But this is a good start.”

Sanders declined to comment for this story. In a statement on Wednesday night, Ellison spokesperson Karthik Ganapathy said: “Keith suggested names for DNC at-large membership and committees. Some were selected, and some were not.”

The new DNC appointments come at a particularly fraught moment for the Democratic Party as it gears up for its first chance at taking back power from the Republican Party in the 2018 midterm elections. Right now, the Democratic Party is at one of its low-points in the past century, having lost control of both branches of Congress, the White House, and a majority of statehouse seats. Returning to power will likely require pulling off the unity Perez pledged — a balancing act that may prove tougher to pull off than it appears.

A controversial Sanders ally is not reappointed to a key position

Perhaps the most contentious decision reflected in the new DNC list was to not reappoint Zogby, an outspoken advocate for rights for Palestinians, to the DNC’s executive committee. (Zogby has been frequently critical of Israeli Prime Minister Benjamin Netanyahu and his “unholy alliance” with the American government — a controversial position within the Democratic Party.)

Perez did reappoint Zogby as at-large member for the DNC, which consists of more than 200 members in total. Perez had the authority to merely not appoint Zogby to the DNC at all — an authority he did not exercise. Moreover, Zogby could still run for the executive committee if the rest of the DNC members decide to elect him. (Perez himself was reported unavailable for an interview because he is campaigning in Seattle. Perez consulted Ellison on the appointments, according to one person familiar with the process.) Perez only gets to choose 11 of the DNC’s 67 executive committee members.

Still, Sanders allies also complained about the removal of DNC members Barbra “Babs” Siperstein and New Hampshire Democratic Party Chair Ray Buckley from their positions. (Neither endorsed Sanders in the 2016 primary, but Siperstein backed Ellison and Buckley is viewed by Sanders backers as a neutral arbiter of the New Hampshire Democratic primary when many state party chairs weren’t.)

“There's a lot of upset about the people who were appointed, and I am, too,” Zogby said.

A bit of backstory about what irks Zogby is crucial. Last year, Bernie Sanders and Hillary Clinton agreed to form a “unity commission” that would come up with reforms for the Democratic Party’s presidential nomination process. Its membership — chosen by Sanders, Clinton, and Perez — is supposed to recommend those reforms, which include revamping the system for selecting the controversial superdelegates to the rules and bylaws committee of the DNC. But Zogby alleges that the rules and bylaws committee chosen by Perez is stacked against the Sanders-aligned reformers.

“Not a single person from the Bernie camp is in the new bylaws groups, but five people from the Clinton side are,” Zogby said. “That’s not a way to get unity.”

The DNC rejects this characterization entirely. “This allegation couldn't be further from the truth,” said Michael Tyler, DNC press secretary. “This list had input from DNC members and includes Clinton supporters, Sanders supporters, Democrats who didn't endorse in 2016, new Democratic leaders, leaders who have been part of the party for decades, and those who will help us win. Our priority is to win and that was the purpose of this slate.”

And it does appear clear that Perez made efforts to include the Sanders faction’s wishes with his new raft of appointments. There’s little clear evidence that the new rules members are “loyal” or tied to Clinton in a meaningful way. Moreover, Perez appointed Larry Cohen, a union leader who chairs the Bernie-linked Our Revolution PAC, to an at-large position, as well as former Sanders campaign aide Symone Sanders. And Sanders’s supporters will surely thrill to the high number of union leaders — the SEIU's Hector Figueroa; the UAW's Cindy Estrada; the AFL-CIO's Tefere Gebre — who were appointed to at-large positions.

Other Sanders allies were less pleased, and they pointed at the appointment of long-term Clinton allies like Harold Ickes, Bill Clinton’s chief of staff in the 1990s; and Tony Coelho, best known as a Democratic strategist in the early 1990s.

"It’s alarming. We just had a contested DNC chairs race and now there are fewer party reformers on this committee than there were before the race," said Nomiki Konst, a Sanders ally and lefty commentator who has also served as a member of the unity reform commission. "This is really, really bad.”