Again, the alleged event happened right in the middle of the Packwood sex scandal. The Republicans would've loved to have had it been one of one (one R vs one D). They didn't. If there was any time that it would've been welcomed, that was the time.
Past allegations, of which NONE WERE SEXUAL ASSAULT.
Her story has changed, dramatically. Usually sexual assault victims don't drastically change their stories. They don't hide who did what to them, when they do tell people. They don't all the sudden remember, after years (or even months) of saying it was non sexual, to flat out saying "oh wait, I forgot. I wasn't wearing panty hose and he stuck his hand in my vagina".
Silly me, I forgot.
Not to mention that witnesses accounts don't tend to all agree with everything and then all change their stories after the main witness changed their story.