Republicans are still bullish on confirming Supreme Court nominee Brett Kavanaugh, despite him being accused of sexual assaulting a teenage girl when he was in high school.

Democrats are demanding the FBI investigate the matter, while behind the scenes they are becoming increasingly optimistic that his nomination could sink.

Republican staffers on the Senate Judiciary Committee conducted a call with Kavanaugh late on Monday, even though their Democratic counterparts refused to participate.

WASHINGTON — While Supreme Court nominee Brett Kavanaugh is embroiled in an allegation that he sexually assaulted a teenage girl while in high school, Republicans and Democrats are growing increasingly at odds with what kind of process should come next and putting the appeals judge's confirmation chances on thin ice.

Senators are breaking out into multiple factions:

Democrats would like the FBI to reopen a probe of the allegations from Kavanaugh's accuser, Dr. Christine Blasey Ford.

Most Republicans have carved out their stance that follow-up calls should be made with Kavanaugh and Ford.

Some Republicans want additional testimony from Kavanaugh and to hear from Ford under oath, which would likely delay the necessary procedural vote the committee scheduled for Thursday.

Republican Sen. John Kennedy said Monday, after a meeting of Senate GOP Judiciary Committee members, that there "will be a full opportunity for the accuser and the accused to be heard."

Sen. Dianne Feinstein said in a statement Monday afternoon that the FBI should handle the matter, not Judiciary Committee staff.

"The FBI has the resources and know-how to conduct an objective, independent evaluation of these sensitive allegations with appropriately trained investigators," she said. "This isn’t just about an interview, it’s about analyzing information and gathering the facts. That’s what the FBI does, and that’s why they’re in charge of the background review process."

But Republican staffers have already begun the process. At the direction of the committee's chairman, Iowa Sen. Chuck Grassley, staffers conducted a phone call with Kavanaugh late Monday afternoon, while Democrats refused to take part.

Possibility of additional hearings

While Kavanaugh testified for several days earlier this month, the possibility of additional hearings is becoming more real by the minute. And some Republicans, including one of the only swing votes on Kavanaugh's confirmation in Sen. Susan Collins, want a more in-depth approach to assessing both sides of the story.

"For my part, I believe that it’s very important that both Professor Ford and Judge Kavanaugh testify under oath about these allegations," Collins told reporters on Monday. "And for my part I need to see them and listen to their answers to the questions in order to make an assessment."

The different positions on how to handle the allegations has some Democrats thinking Kavanaugh does not make it through the confirmation process and at risk of losing crucial votes he might need from the Senate's moderate Democrats facing re-election. One Democratic aide told Business Insider that "this gives red state [Democrats] all the cover they need" to not feel pressured to back Kavanaugh, while another thinks he is "toast."

Meanwhile, Republicans are digging in their heels, confident that they can still get Kavanaugh through to confirmation. If they cannot confirm him, many GOP aides believe the next nominee would not be as difficult, as the urgency to fill the vacant seat would increase and Trump could even end up selecting a more conservative nominee.

And Trump himself appeared to not balk at the prospect of delayed hearings, telling reporters at the White House on Monday that if "it takes a little delay, it'll take a little delay."

"But again, this is something that should have been brought up long before this. They had the information in July as I understand it," Trump added. "That’s a long time ago and nobody mentioned it until the other day. You know, it’s very unfortunate they didn’t mention it sooner. But with all of that being said, it will, I'm sure, work out very well."