I'm kinda surprised no one here has mentioned why Ron Paul got asked this question. (If it was mentioned I missed it).

A high up in Ron Paul's previous presidential campaign died from pneumonia. After a 2 month stay in the hospital, he racked up $400,000 in medical bills. He had no money to pay and no insurance. He was young, about 49 years old. The man had been an executive in a CA company for 9 years before leaving CA and re-settling in Texas where he eventually went to work for the Paul Campaign. The man in question had a college degree and a Masters degree but he died penniless and had no health insurance. The media glosses over the fact that he had a pre-existing condition that made insurance too expensive. That pre-existing condition: several internet sites report it to have been AIDS.

I didn't watch the debate but I doubt it was a coincidence that Ron Paul got this question.