Medicaid expansion is a life or death matter for voters in the upcoming midterm elections, according to a newly released study.

While congressional and state-level GOP lawmakers are trying to roll back the Affordable Care Act (ACA), voters in four states—Idaho, Montana, Nebraska, and Utah—will weigh in on Medicaid expansion in November’s midterm elections, voting on ballot measures that would expand access to Medicaid through the ACA, or Obamacare. If the measures pass in Idaho, Nebraska, and Utah, they could save 600 lives every year, according to a study by the Center for American Progress, a progressive think tank in Washington, D.C.

If legislators in all 17 non-expansion states reversed course and expanded Medicaid access, more than 14,000 lives would be saved every year, Rachel West, report author and director of research for the Poverty to Prosperity Program at the Center for American Progress, told Rewire.News.

Since the ACA was signed into law, lawmakers in 33 states and the District of Columbia have passed the expansion, extending coverage to almost 12 million people.

Lives are on the ballot this year, advocates say.

“This election, voters can be heroes and save lives by doing what politicians have failed to do. Politicians may not, but voters understand that everyone deserves access to lifesaving medical care. By empowering Americans to cut through a broken political system, ballot initiatives are poised to save lives this year,” said Jonathan Schleifer, executive director of The Fairness Project, which funds and organizes in support of voter initiatives for progressive issues like Medicaid expansion.

The nonprofit has channeled at least $1.3 million to Nebraska, $2.7 million to Utah, $400,000 to Montana, and $500,000 to Idaho to help get these propositions on the ballot, according to NBC.

Critics of Medicaid expansion, who have turned down billions from the federal government to expand the program, point to high expenses and added taxes, but researchers note that implementing expansion boosts health, economies, and leads to reduced spending on health-care services for the uninsured in the long run.

“As of 2016, Medicaid covered 11.9 million newly eligible Americans in expansion states, reducing the share of nonelderly adults without insurance in these states from 13.6 percent in 2013, the year before expansion, to 8.1 percent. A growing body of research also shows that Medicaid expansion’s benefits extend far beyond coverage and access to care: It also saves lives, reduces families’ chances of facing bankruptcy, and increases access to opioid addiction treatment, among other benefits,” the report states.

But expanding Medicaid has not been easy to do in states with GOP-held legislatures. In Maine, for instance, Gov. Paul LePage (R) refuses to implement the expansion approved overwhelmingly by voters in 2017. About 70,000 Maine residents are still waiting to receive health coverage, as Rewire.News reported.

Idaho voters in the midterms will consider Proposition 2, which would expand coverage to around 62,000 residents. Republicans in the legislature claim it will be too financially burdensome, even though the federal government will pay for at least 90 percent of the cost of the Medicaid expansion in perpetuity. The Work, Not Obamacare political action committee opposes the measure and has raised $29,299, backed by the libertarian think-tank Idaho Freedom Foundation.

In Montana, Initiative 185 would continue the state’s Medicaid expansion that began in 2015 and preserve it for almost 100,000 by increasing a “sin tax” on tobacco products, including electronic cigarettes. Two tobacco companies have poured $17.5 million into the Montanans Against Tax Hikes campaign against expansion, KPAX reports. A new poll indicates that 52 percent of Montanans are in favor of the measure.

In Nebraska, Gov. Pete Ricketts (R) opposes Initiative 427, which would expand Medicaid to an estimated 90,000. Ricketts claims it would divert money from other programs and create a $158 million tax burden. But a recent report found the expansion would create nearly 11,000 jobs and $1.3 billion in economic activity, and generate more in combined local and state revenues than it would cost. While no major PACs are leading the opposition, a lawsuit filed by opponents to keep the measure off the ballots earlier this year was dismissed by the state supreme court in August.

Utah’s Proposition 3 would expand Medicaid coverage to 150,000 people, a significant increase from the existing and more limited expansion plan passed by the majority-Republican legislature that covers about 70,000, according to the Park Record. The expansion would be financed by increasing the state sales tax by a proposed 0.15 percent or from 4.7 percent to 4.85 percent. Despite some Republican opposition, there are no major PACs opposing it. A new poll indicates that 59 percent of Utah voters favor expanding Medicaid.