At the risk of sounding like Comey Jr in here, you can't place this at the hands of the FBI, a week to conduct an investigation on allegations and incidents that occurred three decades ago? It was never about whether they were 100% true, it is simply about there is so much that points to his character being extremely flawed. The real issue is the "culture war" aspect, ie. if old Bart is guilty and wrong, every Senator or almost everyone is wrong and guilty too. Political calculations aside, that is the main issue. If it were drug trafficking or sex trafficking he was accused of, it would be much different.
I can't call how it plays, if I was betting money, I'd say he gets confirmed. There is no one with any real integrity of the Republican side. No one. The real sick part is not who would vote NO, but how that they almost all are voting YES.
And, regarding FBI investigations into sexual assault, they almost never happen, in a case like this. If you have widespread sexual assaults and rapes, across state lines, or in instances like the Nassar case, yes, but a woman who was pinned to a bed, would never be handled by the FBI. There is no federal law being violated, only in fairly unique circumstances.