Steering South Carolina’s uninsured residents away from seeking primary treatment in emergency rooms and into free health clinics is a worthy idea. But it wouldn’t come close to matching the benefits of expanding Medicaid coverage to hundreds of thousands of low-income South Carolinians.

Last week, S.C. House Republicans launched a proposal designed to serve as an alternative to complying with the federal Affordable Care Act, commonly called Obamacare. The proposal would pay hospitals $35 million next year to guide the uninsured to the state’s 20 free federally qualified health clinics.

The plan also calls for giving the clinics $10 million next year to treat those patients. The money would come from $62 million the state Department of Health and Human Services received last year but did not spend.

The plan also includes $20 million – $6 million in state money and $14 million from the federal government – to pay rural hospitals for the entire cost of uncompensated care they provide for low-income patients. Smaller amounts would go to other efforts to expand and improve care, such as $3 million for a program to repay the student loans of doctors who agree to work in underserved areas of the state.

But not a single new person would be insured under the plan. By contrast, expanding Medicaid under the Affordable Care Act would result in about 500,000 more uninsured residents being covered.

While critics are correct in saying that Medicaid suffers from fraud and excess costs, it nonetheless provides essential medical care for hundreds of thousands of families and individuals who otherwise would have no coverage. Expanding Medicaid to cover all those up to 138 percent of the federal poverty level – those who make about $15,000 a year – would be paid for entirely by the federal government for the next three years.

Federal contributions for newly insured recipients would drop to around 95 percent in 2017, and to 90 percent by 2020. For the first time, low-income adults without children would be guaranteed coverage through Medicaid without the need for a waiver.

Despite whatever waste and fraud might occur, the expansion would provide access to medical care to hundreds of thousands more residents at no cost to the state for the first three years. Even as federal funding is reduced, the state still would enjoy, at worst, a 9-to-1 match from the government.

In addition to covering the uninsured, the expansion also would help boost the state’s health care industry and create new jobs. That, in turn, would help stimulate the overall economy.

Gov. Nikki Haley and fellow Republicans in the Legislature have opposed the expansion, saying it would cost the state more than $1 billion in total by 2020. But it would cost the state nothing for the first three years and only a fraction of the billions of dollars in federal money that would pour into the state thereafter.

All in all, according the the Congressional Budget Office, states will pay only 2.8 percent more than what they would have spent on Medicaid if there were no health-care bill at all. The program also would help reduce emergency room visits and the cost of treating indigents, which raise the cost of health care for everyone.

If South Carolina does not take advantage of the federal money, the state’s share will be used somewhere else. The biggest loss, however, would be the lives that might have been saved or improved through access to health care.

Eight Republican governors now have elected to support the expansion of Medicaid in their states. This week, Gov. Chris Christie of New Jersey, a sharp critic of Obamacare, became the latest to embrace the program.

Others include Arizona Gov. Jan Brewer, Ohio Gov. John Kasich, Michigan Gov. Rick Snyder and Florida Gov. Rick Scott. Scott agreed only to a three-year extension of the expansion with the program facing re-evaluation at the end of that period.

That might be an option that Haley and the state’s Republicans could stomach. With the federal government picking up 100 percent of the cost, it would pose no financial risk to the state.

The only conceivable reason to reject the expansion of Medicaid would be to make a hollow political statement in opposition to Obamacare. But that is political grandstanding at the cost of losing billions of federal dollars to other states and denying health care coverage to hundreds of thousands of uninsured South Carolinians.

And that, we think, would be impossible to justify.