THE BIGGEST PROBLEM WITH OBAMACARE IS THAT IT WORKS:

In Idaho, the number of people who signed up for Medicaid has jumped by 13.4 percent. In Georgia, it's up 12.9 percent. In North Carolina, the rate has climbed 12.4 percent.

None of those states opted to expand their Medicaid programs as part of the Affordable Care Act, but all have seen substantial enrollment increases in state health insurance.

The explanation for the change is a phenomenon sometimes called the woodwork effect or the "welcome mat effect." I've written about the idea before: Essentially, people who were always eligible for a public program will often enroll when there's publicity about an expansion. That's what appears to have happened with the Affordable Care Act. Even though state policy wasn't changing everywhere, all the talk about new health insurance options and the resources devoted to helping people sign up led to a surge among people who had always been eligible for the program.

Altogether, enrollment in the nonexpansion group of states has increased by 6.8 percent, or about 1.5 million people.

Of course, the increases in states that have expanded Medicaid are more extreme. In Kentucky, the state with the biggest increase, the Medicaid rolls have grown by 71 percent. Overall, states that expanded Medicaid saw substantially larger reductions in the number of people without health insurance.

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