The prominent conservative organization Club for Growth is readying $20 million to defend House Republicans who rebelled against Kevin McCarthy‘s (R., Calif.) speakership bid in January.

“Moderate donor networks are already working to enact retribution against these conservative members who they perceive to be vulnerable to a primary challenge,” read a memo from the group, first obtained by Politico. “Making our financial commitment public may serve as an effective deterrent to some potential challengers.”

All 20 members of Congress on the list voted against McCarthy’s bid for the speaker’s chair at some point during the turmoil that gripped the chamber at the beginning of the year. “We’re not going to live in the era of the imperial speaker anymore,” said Representative Matt Gaetz (R., Fla.) at the time. McCarthy eventually secured the top post on the 15th ballot but had to make a number of concessions that ensured the rank-and-file would have more involvement in the crafting of legislation.

The list of candidates the Club for Growth will defend includes established names like current House Freedom Caucus chair Scott Perry (R., Penn.) and his predecessor, Andy Biggs (R., Ariz.). Five of the “Patriot 20,” as the Club for Growth put it, are freshman members who may be more vulnerable, including Representatives Josh Brecheen (R., Okla.) and Anna Paulina Luna (R., Fla.). Gaetz and Representative Lauren Boebert (R., Colo.), frequent agitators of McCarthy, are also on the list.

The Club for Growth focuses on economic policy and tax cuts and has been known to buck the Republican establishment. The group endorsed Representative Alex Mooney (R., W.Va.) in the primary to challenge Senator Joe Manchin (D., W.Va.). They did so despite it being widely known that Senate Republican leadership was recruiting popular West Virginia governor Jim Justice to run.

The 20 members in question have frequently bucked leadership on important votes. Members of the House Freedom Caucus attempted to kill the debt-ceiling deal in the lower chamber and instigated a weeklong blockade of House proceedings after they failed to stop the deal from passing.

The caucus has drawn the rebuke of moderate Republicans for wasting everyone’s time, culminating in an explosive conference meeting before the blockade of House proceedings was lifted.

While the Congressional Leadership Fund does not spend against Republican incumbents, the memo may be intended to dissuade McCarthy allies from challenging the more unruly members of the caucus.

“Moderate donors and candidates seeking to settle scores should save their money, because we are prepared to win at all costs,” the Club for Growth memo read.

Most of the 20 are in very safe districts, but some like Boebert are vulnerable to Democratic challengers. Though her seat leans Republican by seven points, the Colorado representative only beat Democratic nominee Adam Frisch 50.1 percent to 49.9 percent. Frisch is challenging Boebert again and outraised the representative by nearly $2 million in the second quarter.

With probable changes to the congressional map in Alabama and New York, Republicans may have trouble defending their majority in 2024.