That's the whole goal of the "both sides" attack, for those who do actually deploy it. It takes an issue that people might actually care about and makes it irrelevant. A Republican that cares has no reason to abandon a sexual predator to vote for another. (Or in Hillary's case a supporter of a sexual predator.)
Also, if anything, the attitude of the Democratic party towards Bill Clinton indicates that Democrats don't care about sexual crimes. I don't think it's really that simple though.