Trump urged Alabamians to vote for Moore during a Friday-night rally in neighboring Florida.
"We can not afford, the future of this country can not afford to lose the seat", Trump said referring to his party's narrow 52-48 advantage in the Senate. "Love, Roy Moore D.A". We want conservative judges, like Judge Gorsuch on the Supreme Court.
President Trump has reportedly agreed to record a robocall for Roy Moore.
Mr Moore, who is 70, has been dogged by multiple allegations of sexual misconduct, including accusations that he molested two teenage girls and pursued romantic relationships with several others while in his 30s. US Senate Majority Leader Mitch McConnell, a fellow Republican, tried everything to get a defiant Moore to drop out.
In the interview, Moore again denied the allegations of sexual misconduct against him, and said that he did not know the women who have accused him of sexual assault or molestation.
"The state of Alabama deserves better", Shelby said.
"America is more than just a place on a map", he said.
Commenting on one of his accusers, Beverly Young Nelson, who presented an inscription that she alleges Moore wrote in her years, Moore conceded that "I have written cards, graduation cards". You know the yearbook?
The rest of Trump's speech at the rally was a standard assortment of boasts and attacks. "Did you see that?" She started writing things in the yearbook.
"We can not afford, the future of this country can not afford to lose the seat", Mr Trump said, referring to his party's razor-thin 52-48 advantage in that chamber of Congress.
Trump's words don't just carry political capital.
At a hair salon, Emma Howell, the 21-year-old manager, rolls her eyes at the mention of Moore, saying he has broken the habitual Republican vote among her generation.
Trump endorsed Moore's candidacy despite the claims against him, and has said a Democratic victory would serve a blow to his agenda.
Moore might still lose what should be an easily winnable race for a Republican.
The White House said the rally was a campaign event for Mr Trump. "We can't afford to have a liberal Democrat who is completely controlled by Nancy Pelosi and Chuck Schumer", he added, referring to the top Democrats in the House of Representatives and Senate, respectively. "His decision not to actually travel to Alabama for Moore, then, would seem to be a pretty rough commentary on Moore's chances", Blake wrote.
But on Friday, less than 32km from the Alabama border, Trump erased any plausible deniability he might have had in this US Senate race.