I read that one.
The guy was scum.
And she was a ‘prize’ among the office workers or campaign workers. Meaning she wasn’t at that party that weekend to screw. She was a good girl. It probably took all day and night (heavy drinking, everyone else pairing up) to get her to agree to go for that drive. She wasn’t a good time girl.
I read it when it first came out. Still have a copy. I have always referred to him as “senator Chappaquiddick” ever since. As you said, he was truly scum.