Sharon Cooper is not a national political figure. She is a state legislator in Georgia, one I happened to encounter at a recent event in Atlanta. But Cooper is also an archetype of Obamacare's newest adversary: the state official fighting health care reform on the ground. These officials can't stop the new law from taking effect. The Supreme Court and the presidential election settled that. But they can interfere with its implementation, potentially denying insurance to millions of poor people across the South and the interior West. To accomplish that, they're wielding some specious arguments.

The most critical issue in these places is whether to expand Medicaid, the insurance program for the poor. The federal government provides most of the funding, but states manage the program and have leeway over who can enroll. At the moment, most states limit Medicaid to specific groups of low-income Americans, such as single women with children. Under Obamacare, states are supposed to expand eligibility so that the program includes all low-income Americans. But states don't have to undertake that expansion and lawmakers like Cooper, a Tea Party Republican from the north Atlanta suburbs, are working hard to see that they don't. Because Cooper presides over the Health and Human Services Committee in the state House of Representatives, her opposition makes a difference.

Georgians have a lot at stake in this fight. According to projections from the Kaiser Family Foundation, about half a million additional people would become eligible for Medicaid if Georgia opts for the expansion. And if Georgia doesn't? Then most of those half-million people will have no insurance at all. The fate of these people was very much on the agenda at the meeting where I saw Cooper—the "Health Care Unscrambled" policy breakfast, sponsored by a group called Georgians for a Healthy Future. The group believes in health care reform, as did the majority of people at the event. It was to Cooper's credit, I think, that she agreed to appear and explain her views. (I was also speaking there.) But one of her arguments caught my attention, because in more than a decade of covering health policy I'd never heard it before.

The claim was that people on Medicaid sue their doctors more than people who have private insurance. To check its veracity, I consulted Sara Rosenbaum, a professor at George Washington University and expert on Medicaid. “The opposite is true,” she told me, because poor people have less access to lawyers. If anything, she said, people on Medicaid are less likely to sue. The most comprehensive assessment available, from the U.S. Office of Technology Assessment, backs this up. And while that report dates back to 1992, I could find no more recent analysis. (Nor could I get substantiation from Cooper, despite several requests for comment.)

Cooper's other claims about the Medicaid expansion, though less outlandish, left out key, mitigating details. She said, for example, that the expansion would cost Georgia too much. But the federal government is picking up nearly the entire cost of the Medicaid expansion, and asking the states to bear just a small share. Many states will end up saving money, because they'll be able to spend far less on clinics and other providers of uncompensated care. The math doesn't work out quite so neatly for Georgia, according to the Kaiser Foundation analysis; the state would have to spend a little extra money. But the difference would be tiny: State expenditures on Medicaid would rise by just 4 percent.