President Trump's endorsement of Alabama Senate candidate Roy Moore triggered a flood of financial support, as America First Action invested $1.1 million in advertising on television and other venues just days before a crucial special election.

The super PAC, affiliated with Trump's official outside group, the political nonprofit America First Policies, saw the endorsement as a signal to enter the race on Moore's behalf. The president's explicit backing of the 70-year-old embattled Republican, accused by multiple women of sexual misconduct decades ago when they were teenagers, could make a difference in an unexpectedly close race to fill a Senate seat in ruby red Alabama.

America First Action's ad buy was scheduled to hit broadcast and cable television in the Birmingham and Huntsville, Alabama media markets, with digital spots and direct-mail ads to follow. The advertisement was still in production on Monday and unavailable for viewing. But an official for the super PAC said they would focus on Democratic nominee Doug Jones' support for "unrestricted" abortion rights.

"Our polling has Moore and Jones neck and neck in the days leading up to this important election. We stand with the president — and against candidates like Doug Jones who seek to obstruct and America first agenda," Brian O. Walsh, president of America First Action, told the Washington Examiner late Monday.

Earlier in the day, Trump endorsed Moore in one of his trademark tweets.

"Democrats refusal to give even one vote for massive Tax Cuts is why we need Republican Roy Moore to win in Alabama. We need his vote on stopping crime, illegal immigration, Border Wall, Military, Pro Life, V.A., Judges 2nd Amendment and more. No to Jones, a Pelosi/Schumer Puppet!" Trump said.

Great America Alliance, the super PAC connected to Steve Bannon, executive chairman of Breitbart News and Trump's former chief strategist in the White House, upped its investment in Moore over the weekend. The group dropped $140,000 on radio, television, and digital advertising, as well as voter turnout activities, to drum up opposition to Jones. Bannon has been a major supporter of Moore's as the retired judge weathered allegations of sexual misconduct.

Moore was on his way to an easy victory in the Dec. 12 special election to fill the remainder of Republican Jeff Sessions' Senate term, when multiple women went public with accusations of sexual misconduct. Among those women was Leigh Corfman, who said she was 14 years old, two years under the age of consent in Alabama, when it reportedly happened. Sessions resigned from his seat to become U.S. attorney general in February and Moore defeated appointed interim Sen. Luther Strange for the Republican nomination in September.

Senate Republicans have urged Moore to withdraw from the race and threatened expulsion from Congress if he won. Trump, who endorsed Strange over Moore in the Sept. 26 GOP primary runoff, initially steered clear of the former judge after the sexual misconduct revelations. Moore's poll numbers plunged despite his vociferous denials.

But as Republican voters absorbed the news and Moore's support improved — he now leads Jones in the polling averages — the president dropped his opposition, tacitly endorsing Moore just before Thanksgiving. The unequivocal backing was delivered Monday on Twitter, followed by a telephone call to offer Moore support and encouragement. Dean Young, Moore's adviser and close personal friend, said the candidate was grateful for Trump's support.

"If we did lose some people, President Trump really helps us get them back on board," Young said.

Moore relayed Trump's message to him, from their phone call, in a Tweet.

"'Go get 'em, Roy!' - President Trump," tweeted Moore. "Just got off the phone with President Trump who offered his full support and said he needs a fighter to help him in the US Senate. I look forward to fighting alongside the President to #MAGA!"

A Democratic operative monitoring the race questioned whether Trump's unqualified endorsement of Moore would affect the race. The strategist said that Alabama voters interpreted Trump's tacit endorsement two weeks ago as a real endorsement, making the president's latest comments less meaningful.

"I don’t think there is any impact, because in everyone’s mind Trump had already endorsed him with his comments from the past. It was already baked into the cake," this Democrat said.