Sondra Carlile, a volunteer at the Baptist Mission Center clinic, checks on uninsured patient Janet Williams, 48, in the clinic's waiting room. (Mei-Chun Jau -- For The Washington Post)

The health law's individual mandate survived a huge hurdle last month when the Supreme Court declared it constitutional. But does that mean the requirement to buy health insurance will actually work?

Sandhya Somashekhar went to Oklahoma -- where a quarter of the population fails to comply with the requirement to purchase car insurance -- to find out:

When it comes to health insurance, the effort to sign people up isn’t likely to get much help from the state. Antipathy toward President Obama’s signature health-care overhaul runs so deep that when the federal government awarded Oklahoma a large grant to plan for the new law, the governor turned away the money— all $54 million of it.

The idea that the federal government will persuade reluctant people here to get insurance elicited head-shaking chuckles at Cattlemen’s Steakhouse, an iconic old restaurant in the Stockyards City neighborhood, which is lined with street banners reading “Where the Wild West still lives.”

“That kind of frontier mentality maintains in Oklahoma, and it’s not a bad thing. It’s a good thing,” said Mark Cunningham, 64, an Army veteran having breakfast with a couple of friends in a dimly lighted booth recently. Considering the car insurance statistic, he said, “I suspect they’re going to run into the same kind of trouble on health insurance.”

Most of what we know about Obamacare's individual mandate comes from Massachusetts. There, compliance has been incredibly high: 96 percent of those who filed taxes last year indicated they had coverage.

Massachusetts, however, is not Oklahoma: It's a liberal-leaning state with residents accustomed to government regulation, and the majority of whom support its health-reform law.

We're still about 16 months out from the individual mandate taking effect. There are a lot of groups, most notably Enroll America, working to make Oklahoma's experience a lot like Massachusetts's, with a high level of compliance. The state's low compliance with auto insurance suggests that it's one thing to have regulation -- and quite another to have Oklahomans comply with it.