About four years ago, Cecelia "Biz" Spotted Tail felt a lump growing in her lower belly.

"I know something's wrong, I know my body," she says. "I couldn't lay on my stomach because I kept feeling that ball."

Spotted Tail, 53, lives in South Dakota, where she has raised five kids on the Rosebud Indian Reservation. After working in mental health services for many years, she recently started a small business, a flower farm called Bizzie's Bees.

Spotted Tail says it took months for an Indian Health Service gynecologist to take her concerns seriously. By the time she would get it removed, the benign tumor inside her uterus weighed 8 pounds. She wanted a minimally invasive surgery.

It cost $54,000. She had no health insurance.

Expanding health coverage for hundreds of thousands of uninsured Americans is a driving issue in some statewide campaigns this election. South Dakota is one of 12 states that has not expanded Medicaid coverage after the Affordable Care Act increased how many low-income Americans could qualify. Next month, voters will decide whether to amend the state's constitution to do that.

In other states, Democratic candidates for governor are promising to expand Medicaid and hammering Republican incumbents for not having done so already.

Spotted Tail's experience speaks to challenges within IHS and also to the struggles many uninsured Americans face. IHS receives so little funding that it often cannot afford to pay for expensive treatments off the reservation unless it is to save a life or limb.

After Spotted Tail pleaded with IHS administrators, she says they agreed to pay for her surgery. But the experience spurred her to become one of the faces of the campaign to expand Medicaid in South Dakota. Research from other states shows expansion can increase health care resources across all patients who belong to tribal nations.

South Dakota's Republican leadership does not want to expand Medicaid

If successful, South Dakota will be the latest in a string of states where ballot measures have bypassed mostly GOP-led state governments in order to expand Medicaid.

"South Dakota is such a rural state, it can be difficult to get to a doctor under any circumstances. If you're uninsured, you're just going to put off receiving that care," says Zach Marcus, campaign manager for South Dakotans Decide Healthcare, a group backing the amendment. It receives funding from hospital systems and health-focused non-profits, according to the campaign finance watchdog site Open Secrets.

If successful, Amendment D would extend publicly funded insurance to 42,500 South Dakotans, according to a legislative analysis. Currently, a single parent of two must make less than $10,590 a year to get Medicaid in South Dakota, according to the Center on Budget and Policy Priorities. That's well below the federal poverty line. The amendment would raise that cutoff to nearly $32,000.

While some business groups have endorsed the measure, Republicans in the state legislature have lined up against it.

"I don't think more welfare in South Dakota is going to make it stronger. Putting [Medicaid expansion] in the constitution is way past ridiculous," state Sen. Lee Shoenbeck told South Dakota Public Broadcasting earlier this year.

Democrats hope Medicaid expansion can help them win

In Texas, 771,000 residents live below the poverty line but still make too much to qualify for Medicaid, according to the Kaiser Family Foundation.

Democratic candidate for governor Beto O'Rourke has slammed incumbent Gov. Greg Abbott for failing to extend coverage to these constituents, pointing to the tens of billions of dollars in federal subsidies for expansion the state has turned down. The O'Rourke campaign is even running a 30-second television spot featuring a trauma surgeon, called simply "Expand Medicaid."

Abbott called Medicaid "broken and bloated" back in 2015 and has not waivered in his opposition to expanding the program.

In Georgia, Stacey Abrams, the Democratic nominee for governor, has attacked Gov. Brian Kemp for his support of a narrower from of expansion.

"He has decided that half a million Georgians don't deserve to wake up and take care of themselves and their families," Abrams told supporters while speaking at a campaign event this summer.

Under Kemp, Georgia is implementing a policy that would make a smaller number of state residents, about 50,000, eligible for Medicaid if they follow work requirements.

In both states, polling shows a majority of voters support expanding Medicaid.

This issue is becoming less partisan over time

Even if Democrats flip these governors' offices, they will need Republican support to fulfill their campaign promise.

In Kansas, incumbent Democratic Gov. Laura Kelly has vowed, if reelected, to attempt to expand Medicaid for the fifth time. Her challenger, GOP state Attorney General Derek Schmidt, opposes expansion because it does not include a work requirement, his spokesperson told the Kansas Reflector.

Support for the policy is nearly unanimous among Democrats – and high among Republicans – so it makes sense Democrats want to use it to woo voters, says Jamila Michener, an associate professor at Cornell University who researches Medicaid and politics.

"Elected officials ... should not be able to ignore the preferences and needs of their constituents," she says.

That popularity also means partisan opposition is eroding, says Adam Searing, an associate professor at Georgetown University who has advised states on Medicaid expansion.

He points to Republicans in North Carolina recently coming out in favor of expansion.

"They were reading the political tea leaves," says Searing.