The 'trailer trash' comment was about Paula Jones, was it not? Was it ever definitively proven that Clinton harassed her?
Don't recall whether it was specific to Paula or generic to the many who accused Bill of sexual harassment. As for proven, most of the cases are "he said/she said", unless there were state or federal secret service agents present at the alleged times who could testify. The semen stain on the blue dress, however, is about as definitively proven as it gets, and lends credibility to the earlier accusations.
I'm not saying he didn't, but in Hillary's mind, if there is even a shred of doubt that she can cling to, she probably is. Don't underestimate the power of cognitive dissonance. Kind of like how Bill Cosby's wife totally supports him, despite all the claims from other women that they were harassed and drugged and even his own deposition showing he was unfaithful and had been prone to give drugs to women when dating.
Cognitive dissonance can indeed be an issue, and it's worth examining how various candidates handle it. E.g.,
Carson and pyramids being used as granaries vs. as tombs, or
Trump and any number of issues (treatment of women, self-image, etc.), or
Clinton and sexual harassment of women by men in positions of power,
etc.