While it's a little embarrassing these days to have been a big John Edwards supporter, I'm quite proud of how the Democratic Party taught itself about health care policy in the 2008 primary. We learned that individual mandates were necessary to prevent adverse selection from making insurance unaffordable after you prevent insurance companies from charging people with pre-existing conditions more. It wasn't just a thing a few health policy wonks knew. I heard it from friends of mine at Drinking Liberally and at the philosophy department. They were smart people, but it's not like they had a deep knowledge of health care policy in general. But a grasp on the issues had penetrated so deeply into the party rank-and-file that we generally understood the point of mandates. Obama won the primary, but Hillary (and Edwards) won the debate. So even though mandates look kind of weird at first, Democrats understood them and supported them in Obamacare.
Republicans haven't taught themselves about this, and now the architect of the Congressional Republican health care plan that's supposed to replace Obamacare is promising to regulate against discrimination based on pre-existing conditions, without mandates. Maybe looking into the issue has led Steve Scalise to understand the problem. But even if he understands it, his fellow Republicans certainly don't. That's a bad place to start when you're trying to think up your party's counterproposal.