Former President Donald Trump is weighing whether to pull his support for Rep. Mo Brooks (R-Ala.) in Alabama’s Republican Senate primary. 

After handing Brooks his early endorsement last year, Trump has become increasingly frustrated with the Alabama congressman, according to two sources familiar with the race. 

He has complained privately about Brooks’s remarks at a Trump rally last August suggesting that Republicans should move past the 2020 presidential election and has grown increasingly worried about Brooks’s lackluster performance in the primary. Despite Trump’s endorsement, most polls show a tight race between Brooks and two other Republicans, Katie Britt, a former aide to retiring Sen. Richard Shelby (R-Ala.), and Army veteran Mike Durant. 

"Trump has been angry at Mo ever since the rally he held with him in Alabama last year,” one source familiar with the matter said.

The Alabama congressman is also trailing both Britt and Durant in the money race; his most recent federal filings show that he ended 2021 with less than $2 million in the bank, while Britt had nearly $4.1 million on hand and Durant finished the year with about $2.5 million. 

Trump’s frustration with Brooks spilled out into the open this week, with the former president telling the Washington Examiner that he is disappointed with Brooks. 

Trump said that he had decided to endorse Brooks because of the congressman’s support for Trump’s baseless claim that he was robbed of victory in 2020 by widespread voter fraud and systemic irregularities. But after Brooks’s remarks at the rally last August, Trump began to have doubts about his support.

“I’m disappointed that he gave an inarticulate answer, and I’ll have to find out what he means,” Trump said. “If it meant what he sounded like, I would have no problem changing [my endorsement] because when you endorse somebody, you endorse somebody based on principle. If he changed that principle, I would have no problem doing that.”

One source familiar said that Trump hasn’t yet made a decision on whether to pull his endorsement of Brooks, but added that the former president wanted to put him on notice. The source cautioned that a decision isn’t imminent, but said that he isn’t taking anything off the table.

For his part, Brooks has sought to reaffirm his support for Trump’s claim that the 2020 election was stolen. His campaign released an ad on Thursday touting how he “stood with President Trump in the fight against voter fraud” on Jan. 6, 2021, the same day a mob of Trump supporters stormed the U.S. Capitol in a bid to block the congressional certification of the electoral vote.

Britt, meanwhile, is poised to get a boost from her former boss. Shelby told Politico that he’s preparing to transfer as much as $6 million into a super PAC supporting Britt’s Senate bid.

--Tal Axelrod contributed.