Sen. Marco Rubio on Monday said Roy Moore's accusers are "very credible" and the Republican Alabama candidate for Senate has done nothing in recent days that is "convincing or helpful."

"I think these charges are very serious," Rubio said on Fox & Friends, his most expansive comments on the matter.

"I think these accusers are very credible. And I don't think, quite frankly, that Judge Moore has done anything in the last 10 days that has helped his cause or in any way lowered some of the anxiety that's out there about it.

"I think we're going to learn even more as this goes on, and even if he's elected to the Senate, I think there's going to be a process … that could reveal more and be very potentially problematic for him. In fact, I guarantee it would be."

Rubio was also asked about Democratic Sen. Al Franken and said it's "unacceptable" and the Ethics Committee would investigate.

Presumably Rubio wanted to talk about tax reform and the discussion briefly touched on his idea to increase the child tax credit. Rubio says it needs to be made refundable, which the Senate plan does not do.

But Fox & Friends hosts wanted to talk about Jeff Flake's comments about Donald Trump and Roy Moore.

"He's truly a principled, conservative guy," Rubio said of Flake. "But this is the stuff they talk about — and I don't mean to critique you guys, I'm not saying you in particular — this is the stuff they focus on in New York studios every morning.

"But people this morning got up and went to work. And I think many people feel that a lot of what's going on in Washington is just being exaggerated. They may not agree with every tweet the president puts out or every word he says, but they also see how everything he does elicits kind of this overreaction on the part of some in the media."