MONTGOMERY — Club for Growth PAC, the campaign arm of the Washington, D.C.-based conservative group, endorsed Congressman Mo Brooks, R-Huntsville, in the race for U.S. Senate.

The group announced the endorsement in a tweet Monday, setting off a war of words in this already-heated race to replace retiring U.S. Sen Richard Shelby.

“Mo Brooks has proven to be a strong economic conservative who is unafraid to stand up to Democrats and Republican Leadership to fight for the best interests of the people of Alabama,” the tweet said.

“I am honored and thankful for Club for Growth’s endorsement,” Brooks said in a press release.  “Their endorsement is yet another third party confirmation that Mo Brooks is the fearless fighting conservative America needs in the U.S. Senate.”

The endorsement hardly comes as a surprise as Club representatives last week leaked an April poll it had commissioned showing Brooks leading the field at the time.

Club is known for aggressively playing in primaries, and its benefit comes not just from supporting its preferred candidate but attacking the others. During Alabama’s 2020 primary elections, Club attacked Republican Bradley Byrne in the Senate race and Jerry Carl in the District 1 House race. Byrne would fall short of making the runoff while Carl went on to be elected to Congress. The group also supported Barry Moore, who went on to be elected to Congress from Alabama’s 2nd District. Club eventually endorsed Tommy Tuberville in the primary runoff against Jeff Sessions.

In Brooks’ press release Monday night, it was clear who his and, perhaps, Club’s attacks would be aimed at: Katie Britt, the former Shelby chief of staff and Business Council of Alabama CEO who announced her candidacy last week.

“In Alabama’s U.S. Senate race, the Establishment, Never Trump, cheap foreign labor, debt junkie, tax and spend wings of the Republican Party are ALL coalescing their big-time money on professional lobbyist Katie Britt,” Brooks said in the release.

Asked to respond to Brooks’ broadside, Britt reiterated her support for the state’s agriculture, military and business interests, which oftentimes aren’t in line with the Club’s vote scorecard.

“Bless his heart, there he goes again with Mo’ lies,” Britt said in a statement. “As a first-time candidate, I’m not surprised that the Washington, D.C., super PACs have decided to back my opponent, who’s been in office since 1982. I have made it clear that I’m going to put Alabama First — and out-of-state special interests have obviously gotten the message.”

Brooks himself was accused of being anti-Trump during his run for Senate in 2017 due to his previous comments calling Trump a “serial adulterer” and “notorious flip-flopper.” Much has changed since then as the former president in April endorsed Brooks’ candidacy for the current Senate race.

Club for Growth itself has been accused of being anti-Trump in the past. Upon being attacked in 2020, Byrne noted that Club spent $7 million on attack ads against Trump during the 2016 GOP primary.

Former Ambassador Lynda Blanchard is the other announced candidate so far in the 2022 Republican primary for U.S. Senate. The election is May 24, 2022.