Sen. Richard C. Shelby, who serves as Alabama's senior senator, said repeatedly Sunday that the state's fellow Republicans can “do better” than Roy Moore, the conservative judge accused of sexual misconduct who faces Democrat Doug Jones in Tuesday's special election for the U.S. Senate.

Shelby has previously said he was not supporting Moore, but his words on CNN's “State of the Union” on Sunday offered a fresh denunciation of his party's nominee just days before Alabamians go to the polls in an election to replace former senator Jeff Sessions, who now serves as attorney general.

“I didn't vote for Roy Moore,” Shelby said. “I wouldn't vote for Roy Moore. I think the Republican Party can do better.”

Shelby encouraged fellow Alabama voters to do as he did on his absentee ballot: to write in the name of another Republican for the office. Jones's chances of victory would be significantly boosted if large numbers of Republicans abandon Moore in favor of various write-in candidates. Shelby declined to name which Republican got his vote.

“The state of Alabama deserves better,” he said.

During a rally in Pensacola, Fla., President Trump tells Alabamians to “get out and vote for Roy Moore,” the Republican nominee for U.S. Senate in Alabama. (The Washington Post)

Shelby's words come as President Trump has stepped up his involvement in the race. Trump offered Moore, who has been accused by multiple women of making romantic or sexual overtures to them while they were teens and he was in his 30s, a full-throated endorsement at a rally just over the border in Florida on Friday. And Trump plans to record a robo-call on Moore's behalf.

But Shelby said he finds Moore's accusers believable.

“There’s a time, we call it a tipping point. I think there have been so many accusations, so many cuts, so many drip, drip, drip — when it got to the 14-year-old's story, that was enough for me,” he said of the allegations by Leigh Corfman, who told The Washington Post that Moore touched her sexually when she was 14. “I said, 'I can't vote for Roy Moore,'” Shelby added.

Jones has been using the critical remarks from Moore's Republican colleagues to try to persuade Alabama Republicans to cross party lines and vote for him, including in a television advertisement featuring Shelby's words from another interview.

On Sunday, Shelby said that should Moore win Tuesday, he will probably be seated in the Senate but that an ethics investigation is already being contemplated that could result in his being denied the opportunity to serve. “I think the Senate has to look at who's fit to serve in the Senate,” Shelby said.

In a separate interview, on “Fox News Sunday,” Rep. Barbara Comstock (R-Va.) said that if Moore won the election, he'd be “facing the Ethics Committee" immediately. She was disappointed, she said, when the president and the Republican National Committee made the call to back Moore.

“It doesn't represent me,” Comstock said. “I don't think it represents most of the Republican women.”

On "Meet the Press," Sen. Tim Scott (R-SC) reiterated he believed Moore's accusers, and suggested that he'd make a call on whether to expel Moore if he got to the Senate and the accusations were fully vetted.

"The Constitution requires us to, if he wins, seat him," said Scott. "Then there will be an ethics investigation, where we can look into all the issues, and perhaps even talk with some of the folks who are witnesses. That will give us a clearer picture."

Scott, the only black Republican member of the Senate, also passed on a chance to criticize Jones over a mailer he'd sent to black voters this week -- an image of a skeptical-looking black man asking what Alabamians would do "if a black man went after high school girls." Confronted with the ad, Scott suggested that the race had descended into "the gutter," but argued that the main question facing voters was whether they believed Moore's accusers.