The big Republican idea to bring down health-care costs is to "let families and businesses buy health insurance across state lines." Jon Chait has some commentary here, but I want to simplify a little bit.
Insurance is currently regulated by states. California, for instance, says all insurers have to cover treatments for lead poisoning, while other states let insurers decide whether to cover lead poisoning, and leaves lead poisoning coverage -- or its absence -- as a surprise for customers who find that they have lead poisoning. Here's a list (pdf) of which states mandate which treatments.
The result of this is that an Alabama plan can't be sold in, say, Oregon, because the Alabama plan doesn't conform to Oregon's regulations. A lot of liberals want that to change: It makes more sense, they say, for insurance to be regulated by the federal government. That way the product is standard across all the states.
Conservatives want the opposite: They want insurers to be able to cluster in one state, follow that state's regulations and sell the product to everyone in the country. In practice, that means we will have a single national insurance standard. But that standard will be decided by South Dakota. Or, if South Dakota doesn't give the insurers the freedom they want, it'll be decided by Wyoming. Or whoever.
This is exactly what happened in the credit card industry, which is regulated in accordance with conservative wishes. In 1980, Bill Janklow, the governor of South Dakota, made a deal with Citibank: If Citibank would move its credit card business to South Dakota, the governor would literally let Citibank write South Dakota's credit card regulations. You can read Janklow's recollections of the pact here.
Citibank wrote an absurdly pro-credit card law, the legislature passed it, and soon all the credit card companies were heading to South Dakota. And that's exactly what would happen with health-care insurance. Ezra Klein - Selling insurance across state lines: A terrible, no good, very bad health-care idea