Bernie Sanders doesn't have a law degree.
Apart from Dr "I probably take too much of my good stuff" Carson, I can't think of a GOP candidate who didn't have a law degree, or an undergraduate humanities/liberal arts/social sciences degree.
Herman Cain and Rand Paul are both non-lawyers. Cain actually has an undergrad degree in mathematics and a masters of computer science, surprisingly.
The vast majority of GOP candidates (with few exceptions) either have law degrees or non STEM undergrad degrees. There, happy?
The vast majority of candidates have either law degrees or non Stem undergrad degrees
Mitt Romney and Donald Trump both have business degrees. I'm not saying I do or do not support them but they are not social science/humanities/liberal arts. Unless you count business as liberal arts.