Pro-Hillary Clinton groups spar ahead of potential presidential campaign announcement.
Washington CNN  — 

The rift between two super PACs backing Hillary Clinton remains raw and wide, despite their public efforts to appear as though they have mended fences.

Priorities USA and American Bridge, two super PACs readying donors and research for an all-but-certain presidential run by Hillary Clinton, are at odds after a private dispute over fundraising turned public and acrimonious over the last several days, according to a source familiar with discussions between the two groups.

David Brock, longtime Clinton defender and the founder of pro-Clinton messaging group Correct the Record and liberal opposition research juggernaut American Bridge, resigned from his position on the board of Priorities USA, the leading pro-Clinton super PAC tasked with securing large donor contributions. His return to the board is uncertain as discussions between American Bridge and Priorities USA have been unable to resolve the estrangement, according to the source.

READ: Dems make up after Hillaryland spat

Brock quit the board Monday in protest of a New York Times story published Friday that questioned the fundraising practices of his groups, specifically that they pay a 12.5% commission to fundraising adviser Mary Pat Bonner for the donor loot she delivers. It’s a practice Brock stands by.

In a letter to Priorities USA co-chairs Jim Messina – who managed President Barack Obama’s 2012 re-election campaign – and former Michigan Gov. Jennifer Granholm, Brock alleged that current and former Priorities officials had pedaled the story to the Times to damage him. Those officials denied leaking the information, according to multiple sources.

Monday night, as the internal spat became public and created an aura of infighting and dysfunction around the pro-Clinton outside groups, Democrats close to Clinton intervened, urging both sides to make amends. Granholm and Brock released hurried statements pledging to hammer out their differences.

But on Tuesday, the feud was alive and well, as concerns surfaced that Priorities fundraising efforts are falling short, according to a story first reported by Politico.

Priorities fundraising goal for the first three months of 2015 is to secure up to 50 pledges of $1 million each from donors, a source familiar with the targets tells CNN. Almost halfway to the fundraising quarter, Priorities has secured less than 10 such pledges, due, the source says, to the PAC lacking a designated heavy-hitter who focuses full-time on fundraising.

“They’re nowhere,” the source told CNN. “It’s terrible. They have to figure this out because you see what the Kochs are doing,” referring to the Koch brothers, conservative billionaire mega-funders.

Priorities’ overall goal is to raise $300-$500 million for 2016, but according to the source, there are some within Clinton’s orbit that think the goal should be higher given the Clinton name and the family’s fundraising ability. Some at Priorities, according to the source, are concerned that they will not be able meet expectations.

Officials at the super PAC dispute these numbers.

“We haven’t put out any fundraising number,” a source close to Priorities USA said. “That is a fabricated number.”

Sources won’t, however, acknowledge how much they hope to raise. Priorities senior adviser, Paul Begala, promised the PAC will be a big player in the next presidential cycle.

“We will play a critical role in electing a Democratic President in 2016,” Begala said. “Anyone who doubts us should ask President Romney.”

The dispute puts a potentially irreparable crack in the veneer of cooperation that these outside groups have projected over the last year.

Priorities USA and American Bridge, along with Ready for Hillary, the small donor PAC dedicated to building a list of potential Clinton supporters and voters, have largely worked together. Operatives close to Clinton and Obama populate the groups, cross-pollinating on boards and in advisory roles. The relative harmony with which they have operated has been a source of pride for Clinton backers, still scarred by the internal feuds that marked her failed 2008 campaign, even as the super PACs operate outside of Clinton’s small inner circle of confidantes.

“It’s an unfortunate thing because this is now going to be part of the narrative around Hillaryland,” said one Democratic operative, “and her team really had nothing to do with it.”