The real issue is that more than likely people during the time he was active knew he was a perv, but let it slide because he was of value politically.
His political value to progressives now is zero because while he supported immigrant rights and farmworker rights, his support was limited to LEGAL immigrants. He saw illegals as competition to people who followed the rules, and that argument is something the left has been trying to dismiss for decades now.
What I want to know is why now has this finally been broached in public? Again, people knew he was a creep, and he's been dead for 30 years. My question is, cui bono?