Actually it isn't. It's two charges of a serious nature, conflated with a bunch of ho-hum claims of dating 18 and 19 year old women.
Only the two accusations are serious, and when we examine them, we find all sorts of red flags in both claims.
The fact he dated these young women added a creep factor and showed he had issues.
Wouldn't be a creep factor without those other serious charges giving it weight.
The fact he did not confidently defend himself may have led some people to believe he did the things he was accused of.
Yes, he didn't do a very good job in dealing with this, but I think this is because he's not a professional politician, and doesn't know how to side step these sorts of "gotcha" attacks.