Reid Wilson is the author of Read In, The Post’s morning tipsheet on politics. If you have a candidate for best state, e-mail him at reid.wilson@washpost.com.

Most Americans disapprove of the Affordable Care Act and its mandate requiring adults to purchase health insurance. Despite the opposition, we’re complying with the law: The number of uninsured Americans is dropping precipitously.

No state has made progress faster than Arkansas. A new Gallup survey released this past week shows that the percentage of the state’s population without insurance dropped nearly in half, down from 22.5 percent in 2013 to 12.4 percent today.

Of course, a big part of Arkansas’ success stems from the fact that the state had so much ground to make up. Before the Affordable Care Act, the state’s Medicaid program covered fewer low-income residents than that of almost any other state; the program was meant to cover only children, the disabled and those whose medical bills sapped their cash reserves.

Expanding Medicaid, therefore, made more additional Arkansans eligible than similar expansion did in other states, said MaryBeth Musumeci, associate director of the Kaiser Commission on Medicaid and the Uninsured. Before the expansion, only Texas had more uninsured residents.

The state used various means to identify all those newly eligible enrollees. Authorities contacted low-income residents already receiving Supplemental Nutrition Assistance Program benefits, who would also qualify for Medicaid under the expansion, and helped them opt in to health coverage. And the state ran television advertising during football games and other high-profile events to encourage enrollees.

Arkansas did things a little differently than other states that expanded Medicaid. The Republican-dominated legislature wouldn’t pass a traditional expansion; instead, it mandated that federal money be used to pay premiums for private insurance plans through the state’s marketplace, an alternative proponents dubbed the “private option.” Other states have used federal money for premium support, but not to the extent Arkansas has.

The rate of uninsured Americans has fallen nationwide, from a peak of 18 percent in late 2013 to 13.4 percent today. That number has fallen fastest in states that both accepted federal money to expand Medicaid to cover more low-income residents and built their own health insurance exchanges. In those states, the rate of uninsured residents fell by four percentage points, while in states that either didn’t expand Medicaid or didn’t create their own exchanges, the rate fell by just 2.2 percentage points.

Other states have seen the share of uninsured within their borders plummet, too. Delaware’s rate fell to just 3.3 percent, the lowest in the nation. Seven other states — Kentucky, Washington, Colorado, West Virginia, Oregon, California and New Mexico — all saw declines of more than five percentage points.

Georgia, Mississippi and Texas, which did not expand Medicaid or build their own exchanges, still have the highest uninsured rates in the country. More than one in five residents in these three states remain without insurance, the Gallup report found.

If those states eventually decide to take the federal money, they can look to Arkansas as a model for enrollment.

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