Conservatives oppose federally mandated health insurance benefits (maternity, etc.), but they favor states having the power to mandate such benefits, which they already have. But conservatives (e.g., the Heritage Foundation) say they also favor a nationwide insurance market, that is, competition across state lines, which is not the case today.

The problem is that you cannot have free competition nationwide and state-mandated benefits. Would someone who lives in a state with lots of mandates be free to buy a basic catastrophic policy from a company in a no-mandate state? If not, then there is no nationwide market. If so, then the mandates aren’t really mandates.