This is a case where "defending" him could ultimately give credibility to the accusations.
Don't defend him. Let the process play out.
Let any accuser who wants to make an allegation against Kavanaugh come forward and testify, or make the allegation in a sworn affidavit.
THEY WON'T. That's when the narrative changes completely.
That is the rub. Given it is impossible to prove or disprove whatever happened between two people decades ago in a private setting, leftist operators will feel free to make a false claim.
This is a quasi-judicial event, but IMO as general rule a committee should not consider any sworn affidavit or accept any testimony or other evidence that has no probative value. That would include sworn statements by best buddies or anyone else who has no direct knowledge.