At least six governors, including South Carolina's Gov. Nikki Haley, object to expanding Medicaid coverage under the federal Affordable Care Act.

But before our state jumps on a political bandwagon, we need a clear-headed, thorough examination of the costs and benefits of expanding coverage. And it should be done in the context of the federal law staying in place. We can't be caught unprepared should Republicans fail in their goal to repeal the law.

It also is not a decision Haley can make unilaterally. Lawmakers must make choices.

The U.S. Supreme Court ruled that the federal government can't coerce states into expanding Medicaid coverage by dropping all federal Medicaid funding if they choose not to participate. The law expands Medicaid coverage to those under age 65 with an income up to 133 percent of the federal poverty level (or about $31,000 for a family of four).

The federal government is to pay 100 percent of the cost for the first three years; starting in 2017, it will be gradually reduced to 90 percent. About 17 million Americans would be eligible to receive Medicaid benefits under the expansion; in South Carolina, Medicaid enrollment is expected to increase by about 500,000 people by 2020.

South Carolina now provides Medicaid coverage to parents who make up to 50 percent of the federal poverty level, children whose parents make up to 200 percent and pregnant women who make up to 185 percent. Nearly 1 million people are expected to be enrolled next year under existing guidelines.

Haley and Anthony Keck, director of the state Department of Health and Human Services, say the state's Medicaid costs will increase $1.1 billion to $2.3 billion over the next six years. Looking at it year by year, The (Columbia) State newspaper reports, the additional costs for the health care law start at $55 million in 2014 and go to $278 million in 2020.

Among the factors that must be assessed:

We could see a gap in coverage for people who don't qualify for current Medicaid coverage, but who also don't qualify for subsidies available to those with higher incomes to buy private insurance on website "exchanges."

Federal subsidies to hospitals providing indigent care will be largely phased out by 2020, whether states expand Medicaid coverage or not. That could leave hospitals -- and the rest of us -- picking up more of the tab for unpaid bills. Nationally, hospitals spend about $39.3 billion a year on uncompensated care, about 5.8 percent of all expenses, The Washington Post reports. Federal subsidies totaled $11.3 billion in 2011.

Some of the projected increase in costs includes coverage for people who qualify for Medicaid under current rules. More people who qualify are expected to enroll once the individual mandate goes into effect. Even if the state opts out of the expanded coverage, it would still have to cover these people.

Haley and Keck say they don't want to "jam more people into a broken program." No one wants that. They should continue to work to improve the way primary care is delivered in the state and to reduce administrative costs.

But let's fully understand the ramifications of walking away from billions of dollars to help the state's working poor get heath care coverage.

And if not this, then what? The answer should be specific, doable steps, not political posturing.