In a letter obtained by POLITICO, The Collective PAC — which helps elect black candidates to office — asked major liberal groups like Indivisible and Democracy for America to stop calling for Democratic presidential contenders to distance themselves from single-candidate super PACs. Such groups play an important role in electing candidates of color, they argued, especially in primaries, when the Democratic establishment has often overlooked black contenders and left it to outside donors to bolster their campaigns.

“Whether intentional or not, the effect of what you are calling for is to shut down the one reliable source of revenue for engaging voters of color and for supporting candidates of color,” wrote Quentin James and Stefanie Brown James, the founder and co-founder of The Collective PAC. “One of the few sources of funding for the work to engage voters of color and support candidates of color has come from Super PACs.”

The Collective PAC’s stance is at odds with much of the Democratic Party: Most candidates for president have said they do not want super PACs supporting their bids, and some, such as Sen. Elizabeth Warren, have taken additional steps to disavow the influence of money in politics as they make their case to voters.