Rep. Mo Brooks chided President Trump for endorsing appointed Sen. Luther Strange, his main opponent in the upcoming special Senate election in Alabama.

The primary is Tuesday, and Brooks has been struggling in a contest versus Strange and the former chief justice of the Alabama Supreme Court, Roy Moore. The top two vote getters will advance to a run-off if the winner doesn't clear 50 percent. The race will determine who serves the remainder of Republican Jeff Sessions' term. Sessions left the seat vacant when he retired to become Trump's attorney general.

Strange, who has the backing of Senate Majority Leader Mitch McConnell, R-Ky., and his super PAC, Senate Leadership Fund, has been lobbying Trump for his support. The president finally endorsed Strange Tuesday evening in a Twitter post. It could make the difference. Alabama has been one of the states where Trump's support has been the strongest.

"I respect President Trump, but I am baffled and disappointed Mitch McConnell and the Swamp somehow misled the President into endorsing Luther Strange," Brooks said in a statement. "The President has bigger things going on than a campaign, that's for sure. In any event, while Mitch McConnell and the Swamp managed to mislead the President last night, I still support the America First Agenda, and all the polls show we have momentum. We believe our message will win out over the Swamp and Lyin' Luther."

Brooks was slow to embrace Trump in 2016 after he secured the GOP nomination. The congressman had backed Sen. Ted Cruz of Texas in the presidential primary.