WASHINGTON — Obamacare’s Medicaid expansion could become a major election issue again this year – at least in four states where supporters want to enact or continue the policy through ballot initiatives in the 2018 midterm elections.

Organizers in Montana and Nebraska are collecting thousands of signatures to get the issue on the November ballot, while supporters in Utah and Idaho are awaiting final word from state officials who must validate and tally their petition signatures.

Expanding coverage under Medicaid, the national health plan for low-income and disabled Americans, was a key component of the Affordable Care Act. The 2010 law originally required state Medicaid programs to extend coverage to all non-elderly people who earn up to 138 percent of the federal poverty limit beginning in 2014. States that didn’t comply would lose their federal Medicaid funding.

In 2012, the U.S. Supreme Court ruled that the ACA’s Medicaid coverage requirement was unduly coercive and gave states the option to not participate in the coverage expansion. Since then, 32 states and Washington, D.C., have expanded their Medicaid coverage under the ACA while 18 others have not.

Montana approved Medicaid expansion in 2015, but the policy expires in 2019 unless the legislature reauthorizes it. The ballot initiative would make the expansion permanent and raise taxes on cigarettes and other tobacco products to help pay for it. Montana organizers need signatures from 5 percent of registered voters by June 22 for their proposal to make the ballot.

Nationwide, 24 states and the District of Columbia allow voters to pursue statewide legislation – either by statute or constitutional amendment – through the initiative petition process.

But with the exception of Florida and Mississippi, the option is unavailable in the South where poorer states have high uninsured rates and a less-healthy population. It’s also where opposition to Medicaid expansion is strongest.

In the 2017 America’s Health Ranking, a state-by-state analysis of residents’ health based on 35 measures, the 10 lowest-scoring states are all in the South. Mississippi finished last.

“There’s never been anything that makes more sense for the most impoverished, worst-health outcome state in the nation than Medicaid expansion,” said Mississippi State Rep. Steve Holland, a Tupelo Democrat who has long advocated for the policy. “We haven’t done anything with (a petition initiative for Medicaid expansion) yet. But I’d love to see it done because I’m fully convinced it would pass by a pretty good margin.”

But Republican state Rep. Joel Bomgar, vice chairman of the Mississippi House Medicaid Committee, said it makes no sense to expand Medicaid because the program is economically unsustainable – both for the federal government and for states. The expansion would add an estimated 300,000 people to the program in Mississippi.

“Eventually it breaks the back of the American economy. A program has to be working and it has to be sustainable to be expanded. Medicaid is not sustainable on its current footing,” he said.

The renewed activism on Medicaid began in Maine, where the state Legislature voted five times to expand Medicaid coverage, only to have Republican Gov. Paul LePage veto the measure each time. Maine voters passed the Medicaid expansion by ballot initiative in 2017.

And even though LePage was sued in April for once again refusing to implement the policy, Maine’s ballot campaign victory prompted Medicaid supporters in the other four states to pursue similar efforts.

If those ballot initiatives are successful, even more states could see Medicaid ballot initiatives in 2020, a presidential election year when voter turnout typically spikes.

“Initiatives are very susceptible to trends,” said Josh Altic, who directs the ballot initiatives project at Ballotpedia. “When you succeed in one state with a policy that’s applicable across lots of states, it becomes a lot more attractive to try that through the initiative process.”

Of the 18 states that haven’t expanded eligibility for Medicaid, 10 are in the South.

Recent polling by the Kaiser Family Foundation showed 54 percent of Republicans in non-expansion states want to keep Medicaid as it is, while 75 percent of Democrats and 57 percent of independents in those states want to expand the program.

Next to education, Medicaid is the largest expenditure for most states. And many Republicans, already wary of growing entitlement programs, fear that an expanded Medicaid base would limit spending for other vital services. In addition, the Medicaid expansion would provide coverage to childless adults at time when Republicans want the program to serve mainly vulnerable populations like children, pregnant women and those with disabilities.

As Medicaid rolls grow under expansion, states will spend more for coverage. But the higher state spending would be partially offset by savings on hospital indigent care. In addition, the federal government has promised to pay 90 percent of medical costs for newly eligible enrollees under the expansion.

But Bomgar said he doesn’t trust that promise. “In its current form, there is no plan to pay for that 90 percent without borrowing the money,” he said.

For a constitutional amendment on Medicaid to reach the ballot in Mississippi, it would require petition signatures equal to 12 percent of the votes cast for governor in the last election. And in order for the measure to pass, the winning votes must tally at least 40 percent of votes cast in the most recent election.

After the signatures are in, but before the proposed amendment is placed on the ballot, however, Mississippi law allows the legislature to “hold hearings and propose alternatives to the citizen initiative,” according to a state handbook. “The legislature cannot veto or amend the original citizen initiative, but it can pass an alternative that will appear on the ballot alongside the original initiative.”

That’s what happened in 2015, when initiative sponsors tried to pass Initiative 42, a constitutional amendment on school funding. The measure was defeated, supporters said, partly due to the ballot’s competing proposal – Initiative 42A.

Mississippi House Speaker Phillip Gunn did not respond to questions about how Republicans might respond to a similar petition drive on Medicaid expansion.

In order to get a constitutional amendment for Medicaid expansion on the ballot in Florida, supporters would have to collect signatures totaling 8 percent of the votes cast in the most recent presidential election. And for the measure to pass, it must garner a 60-percent supermajority of votes.

In late 2017, Florida state Sen. Annette Taddeo, D-Miami, and state Rep. Lori Berman, D-Boynton Beach, tried to get state lawmakers to approve a constitutional amendment for Medicaid expansion. But they couldn’t get a vote on the measure.

“It never got heard in committee and it was very, very frustrating,” Taddeo said. If Democrats win more seats in the Florida legislature in November, Taddeo said she’ll try again in 2019.

But if that effort fails again, Taddeo said she’d work with stakeholders to get a citizen-led constitutional amendment in 2020.