Repubs either have something (Or know about something) or they are just appeasing a handful of undecided. Either way, Kavanaugh, if he gets in, will have this 1982 accusation over his head (Which doesn't matter anyway for his job), however, will be a perpetual campaign hammer for years to come for the dems.
That is the biggest problem in all of this (And not aggressively challenging the accusations), because this will happen again and again.
Besides, I'm not even sure this cuts against Republicans. Did you read the S.E. Cupp op-ed in the NY Daily News?
Nothing can change that. If it were proven beyond the shadow of a doubt that Kavanaugh is innocent of all charges, there would still be legions of leftards (i.e. ugly leftist women) who would continue to wear their "I believe Christine Blasey Ford!" buttons. No matter what happens with Kavanaugh, the left will contiue this strategy of bogus accusations ad infinitum.
So we may as well confirm Kavanaugh.