The battle over Obamacare's most popular program just hit a wall in a key state

Kansas lawmakers on Monday failed to override Republican Gov. Sam Brownback's veto of a bill that would have expanded Medicaid under the Affordable Care Act.

The Kansas House voted 81-44 to override Brownback's veto, three votes short of the necessary majority needed.

Brownback vetoed a bill last week that proposed expanding Medicaid, the government-run health program that provides insurance primarily to pregnant women, single parents, people with disabilities, and seniors with low incomes.

"I am vetoing this expansion of Obamacare because it fails to serve the truly vulnerable before the able-bodied, lacks work requirements to help able-bodied Kansans escape poverty, and burdens the state budget with unrestrainable entitlement costs," Brownback said in a statement.

Lawmakers have been trying to expand the program under a provision of the Affordable Care Act that opens eligibility up to any adult living under 138% of the federal poverty level - an income of $27,821 for a family of three in 2016.

Thirty-two states, including the District of Columbia, have chosen to participate, leading to more than 11 million people nationwide gaining coverage.

The Kansas House passed the bill in February by the same margin of 81-44, and the Senate passed it on Tuesday by a margin of 25-14.

In the lead up to the vote on the veto override, many of the bill's supporters acknowledged the tall order.

Sen. John Doll, a moderate Republican elected in 2016 amidst a public backlash against Brownback's conservative policies, told Business Insider on Thursday that garnering the two votes needed to override in the Senate would be "really difficult."

"I hope we are able to. I just don't see it," Doll said.

Barbara Bollier, a first-term senator representing several Kansas City suburbs and a retired physician, expressed hope that overwhelming public support for the bill could push some senators and representatives from no to yes.

A public opinion poll conducted by the American Cancer Society in January found that 82% of Kansans support the Medicaid expansion. Several other polls from recent months put the number closer to 62%. Still, it has been hampered, its supporters say, by its association with the Affordable Care Act.

A major supporter of the bill, Doll said that even if an override failed, public support would ensure that Medicaid expansion will be raised by lawmakers again, though probably not until the next legislative session.

"It will come before the legislature again and again until it becomes law. Or until [the ACA] is repealed in Washington," Doll said.

A major obstacle to the bill's passage is its association with the ACA, according to Doll.

"Some of us can't get past the origination of the law," Doll said. "We've got to look past parties and look at policies. We need a big lesson that at every level of government, but especially state and federal. We need to look at what's good for the people."

In his veto memo, Brownback said that an increase in federal Medicaid funding would result in increased funding to abortion providers such as Planned Parenthood and said that because Kansas is "pro-life," he could not support the bill.

Bollier called Brownback's reasoning "disingenuous" and a "weak excuse," noting that amendments to the Medicaid expansion bill addressing funding to abortion providers were introduced in both chambers and were voted down because voters did not support the measures.

"The people have spoken. [Planned Parenthood is] not their issue," said Bollier. "We're a far cry from listening to the people right now."

Bollier also suggested that Brownback's objection to the bill's lack of work requirements for Medicaid recipients was a non-issue because the population gaining coverage is "the working poor."