Transcript for GOP leaders react to Roy Moore allegations

You had four women on the record, 30 sources overall. Going to bring this to Mary Bruce on capitol hill. Mary, this really hit like a bomb in the middle of the day yesterday for senate Republicans and now you've got some senate Republicans also saying Moore should get out no matter what but there is no way to right now get him off the ballot and it's a real dilemma for them. They might lose the seat or face the question of what they do with him if he wins. Reporter: Yeah, George, this puts Republicans in an incredibly tricky position. The condemnation for Moore from the hill is swift and resounding. Almost immediately Republicans said these allegations are disturbing and disqualifying. Now, this seat is crucial to Republicans for maintaining their slim two-vote majority but Moore shows no signs of backing down and too late to replace him on the ballot. If he does win, it's unclear how Republicans here would interact with him. How they would work with him but it is clear Moore would receive a very chilly reception here on the hill. Puts even more pressure on them to get this tax bill done before this race takes place, before whoever wins is seated right now at the time when you have huge differs between the senate and house bills. Reporter: Yeah, George, this is another real political dilemma here. Major differences between the house and senate plan including how they could impact middle class Americans and add to the deficit. Ham Aring this out will be a real challenge and Republicans know they cannot head home for the holidays empty-handed. Mary Bruce, thanks very much.

This transcript has been automatically generated and may not be 100% accurate.