President Donald Trump’s endorsement Tuesday of Alabama Sen. Luther Strange is turning heads, as it represents an outsider president backing the establishment candidate over Strange’s insurgent Republican primary opponents.

“Senator Luther Strange has done a great job representing the people of the Great State of Alabama,” Trump tweeted. “He has my complete and total endorsement!”

Strange has been in the midst of a heated primary in which candidates have been trying to tie themselves to Trump and the senator’s opponents have been distancing themselves from Senate Majority Leader Mitch McConnell.

A public poll released Monday shows that former Alabama Supreme Court chief justice Roy Moore is leading with 30 percent heading into the August 15 primary. The poll puts Sen. Strange in second with 22 percent, and Rep. Mo Brooks in third at 19 percent. There will be a runoff on September 26 if no candidate gets over 50 percent of the vote.

“I respect President Trump, but I am baffled and disappointed Mitch McConnell and the Swamp somehow misled the President into endorsing Luther Strange,” Republican Rep. Mo Brooks said in a statement.

An Alabama Republican insider echoed Brooks comments and told The Daily Caller that President Trump must have been convinced by high level Washington figures to endorse Strange. Strange, the former attorney general of Alabama, has received millions of dollars in support from a Super PAC controlled by McConnell.

Longtime Trump confidant Roger Stone tweeted, following Trump’s endorsement, “McConnell shitz on [Donald Trump]. [Trump] endorses McConnell’s corrupt anti- Trump US Senate candidate Luther Strange wtf?”