The states are evenly split on whether to pursue Medicaid expansion. (Kaiser Family Foundation)

There’s no shortage of controversy surrounding the president’s landmark health-care law, but one battle has been fought in each and every state: whether to expand Medicaid under the law.

The nation is evenly split — half the states are moving forward with the expansion and half aren’t. In some states, the decision came down from the governor and in others, the legislature. In Montana, the governor was for it, but a mistaken vote — yes one man’s mistake — killed its chances in the state House. But now, a coalition of groups under the banner Healthy Montana Initiative wants to put the question to voters next fall.

“We’ve seen widespread support for Medicaid expansion among many many different groups and individuals in Montana,” says Claudia Clifford, the advocacy director for AARP Montana, one of the groups behind the push.

On Thursday, they began the process of getting the expansion on the 2014 ballot by submitting proposed language for a measure to the Montana secretary of state. The legislative language itself has to be vetted and then the attorney general has to complete a legal review of it. Once done, all the group has to do is go out and collect enough signatures to get it on the ballot. The group says expanding Medicaid would provide affordable healthcare to 70,000 Montanans.

Advocates for the expansion in Ohio had explored a similar option, but ultimately the governor found a way to make it happen. Montana’s efforts could lead the way in putting the decision on whether to expand to voters.

The Affordable Care Act, also known as Obamacare, expanded the definition of who would qualify for Medicaid, which seeks to provide the poor with free or low-cost health insurance. The Supreme Court made that mandate optional in a decision that landed in the summer of 2012, allowing states to opt out. Those that opt in would get expanded federal aid initially, though that expanded aid would shrink over time.

As of late October, states were evenly split on pursuing the expansion, according to the KFF. A July report from the foundation found that the 21 states actively resisting the expansion — some were still debating — were forgoing more than a third of a trillion dollars between 2013 and 2022.

“States not moving forward with the expansion are more likely to see modest increases in state spending over the 2013-2022 period; however, increases in federal funds would greatly exceed increases in state costs. In addition, costs could be offset by reduced spending for uncompensated care, state specific savings and increases in economic activity,” the report found.