My DD just spent this past year at the #4 party college.

While she was not a huge drinker, she was out a lot. Too much. Probably every night. If it's not "partying" per se, which I guess by this thread's definition = drinking, it was just hanging out with friends at their room, going to events. It was non-stop go, go, go. She's not a strong student to begin with so this was devastating to her GPA.
There is TONS of "life" going on at the campus. She got very little sleep and classes were not #1 on her priority. So, by my definition, it was a party hard situation. I was not strict on her at home. She went to anywhere she was invited while in high school. I didn't let her stay out all night, she had a curfew and what not, but I don't believe I was a strict parent that caused the partying. It's just what is important to her right now.
What I have found is that many of these kids that went for the year that I know through coworkers and such, have been suspended after a year. Many have not. There is a line and it seems that many kids can do a lot of partying and still manage the school work.