I was a poli sci major and I had never seen a case book in my life before law school. I even took business law as part of my business core, and didn't know how to brief a case.
Maybe it was just the program at my school, but I took constitutional law I & II, administrative law, sex-based discrimination, and criminal law (which was a mix of criminal law and criminal procedure); all were entirely casebook based (all were the UPS Brown/ Gold trim West Books.) and our exams were all long hypos which we had to issue spot, apply rules, and come to a conclusion. We even had to brief all our cases and turn the briefs in for a grade.
Of course I had the typical political theory type classes that didn't don't do squat for me now, but the ones I mentioned above were invaluable.