There is. Per the leaked deposition he admitted he gave women quaaludes and wine/champagne, not a Roofy, and he didn't drop them in their drinks without their knowledge, he offered them and the women chose to take them. Bill did the equivalent of smoking a blunt and giving a few apple Martinis or a Long Island Iced Tea to a woman he intended to get intimate with, or ordering a woman a bottle of champagne and a plate of oysters at a restaurant. Quaaludes were an aphrodisiac. There were even night clubs that served them before they were outlawed in the 80s. My question is how Bill got his hands on some Quaaludes in 2004 to offer to the Temple intern since they stopped manufacturing them. He must have a stockpile.
That said, I can't speak to his actions after he provided the women with the aphrodisiac. If they rejected his advances and he forced himself on them then that's a crime. I've had drinks with women and taken them on dinner dates with champagne, etc. to set the mood and increase my prospects of sex. I suppose I've just been lucky enough to never have had any of them accuse me of raping them after the fact because they sobered up and regretted or couldn't remember what we'd done and felt I took advantage of them.