President Trump's endorsement of Alabama Senate candidate Roy Moore on Monday marked a victory for the efforts of Steve Bannon, the former White House chief strategist who backed Moore through a sexual misconduct scandal that saw most Republicans abandon the candidate.

Trump's endorsement of Moore came days after the president and Bannon spoke privately, a source close to Bannon told the Washington Examiner. That source did not provide details on what the two discussed when they spoke within the past week.

But Trump's decision to throw his support behind Moore, who faces allegations of pursuing inappropriate relationships with teenagers when he was in his 30s, could tighten a race that had already begun to shift in Moore's favor. Trump withheld strong criticism or praise of Moore in the immediate aftermath of the sexual misconduct allegations, even as Senate Majority Leader Mitch McConnell called for Moore to drop out of the special election contest.

Bannon and his allies did not back away from Moore during the intense controversy that followed the first wave of accusations. The Breitbart News chair had supported Moore in the GOP primary that saw Trump campaign on behalf of Sen. Luther Strange, who was appointed to fill Attorney General Jeff Sessions' seat and then lost to Moore in the primary.

The White House noted that Trump spoke to Moore on the phone from Air Force One on Monday after he endorsed the former state supreme court judge via Twitter.

"The president had a positive call with Judge Roy Moore during which they discussed the state of the Alabama Senate race and the president endorsed Judge Moore's campaign," principal deputy press secretary Raj Shah said in a statement.

The White House did not immediately respond to a request for comment about Trump's contact with Bannon.

Andy Surabian, senior adviser to Great America Alliance and a close Bannon ally, said the president's endorsement Monday marked a blow to McConnell, who supported Strange in the primary and pushed Moore to leave the race over the allegations.

"This is a victory for President Trump's entire America First movement and a YUGE loss for Mitch McConnell and his allies, who did everything in their power to pressure the [White House] to throw Moore under the bus and elect a liberal Democrat in Alabama," Surabian told the Washington Examiner in an email.

"Everyday it becomes more clear that McConnell's influence over the Republican Party is waning," Surabian added. "He has no sway over Republican voters across the country, Senate candidates are embarrassed to be associated with him because of his toxicity and he's been dislodged as the titular head of the party in Washington."

Moore has pledged to vote against McConnell for majority leader should he win the special election on Dec. 12. Polls have shown Moore regaining some support among Alabama voters as the shock of the sexual harassment allegations has subsided.

Trump will not campaign in Alabama on Moore's behalf, but will hold a rally in Pensacola, Fla. before voters head to the polls. The city is close to the Alabama border and shares a media market with voters in that state.