Really. I am sympathetic to all that you say but in the absence of any objective proof I believe it is the proper position to take.
I need proof, I am unwilling to take to word of one over the other. She named four people at the party, one is her friend, and none remember the party or even being there. I am not going to say she made it up, nor am I willing to say he is lying. There is nothing to back her story, that is a problem for me.
You both don't seem to understand the question put before you.
There is no "proof" to be had in the traditional sense, no rape kit, no DNA evidence, and failing memories after a long time. So, the purpose of this exercise is different, as are the deliberations involved.
There are basically two options.
First, the incident did actually happen. It is supremely easy to explain Kavanaugh's behavior, that is, lying about it: He wants that seat on the Supreme Court ("I'm not going anywhere."), and lying about being a sexual assaulter is the way to get there.
Second, it didn't happen. Explain, how Ford got to the point of making the allegation she did. Make a case as convincing as the explanation for Kavanaugh's denials above. What does she have to gain not by making any accusation, but the accusation she actually did make. If you can't, you should lean towards Ford's position, because her account is the more plausible one.
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Oh, and BTW, "We need proof!" is the way how assault in private, without witnesses, went unpunished for times immemorial, how the perpetrators went on to their next exploit, and how women's reputations were tarnished. Time's up for that kind of self-serving (from a male perspective), fake-equitable procrastination. In Kavanaugh's case we actually have at least two independent accusations of assault, and for neither is there any evidence even hinting at a political plot bringing it to life.