Let's examine this a bit. Innocent until proven guilty goes all the way back to Mosaic Law and the requirement of two or three witnesses.
Deuteronomy 19: NASB
15“A single witness shall not rise up against a man on account of any iniquity or any sin which he has committed; on the evidence of two or three witnesses a matter shall be confirmed. 16“If a malicious witness rises up against a man to accuse him of wrongdoing, 17then both the men who have the dispute shall stand before the LORD, before the priests and the judges who will be in office in those days. 18“The judges shall investigate thoroughly, and if the witness is a false witness and he has accused his brother falsely, 19then you shall do to him just as he had intended to do to his brother.
What's lacking in all three separate accusations is just one more witness. Been bleeding that all over this thread and a few more. All the Democrats have to do is get one more sworn statement or witness that says yep Kavanaugh was there, the woman was there , and he did that. One more....Then the dialogue would be about perjury---and that is based on the quality and volume of the evidence.