A contentious legislative battle in Montana ended this week, after the state's GOP-controlled House voted to accept federal funding to expand Medicaid to the working poor – a feature of the Affordable Care Act, also known as Obamacare, that Republicans had vigorously opposed.

A House committee originally voted down the measure to expand the access to Medicaid, but supporters succeeded in using procedural rules to bring the bill to the floor on Thursday. Thirteen GOP moderates broke with party leadership to back the measure, which passed 54 to 46.

Now the House and Senate must reconcile one amendment before the legislation lands on the desk of Gov. Steve Bullock, a Democrat, who is expected to sign the bill into law.

But while this latest decision may appear to be a victory for those urging all states to accept federal dollars for Medicaid expansion, the harshness of the debate marked how controversial the issue remains here and in other conservative states.

For many Republicans, the move to expand access to Medicaid amounts to an endorsement of Obamacare and a larger government role in health care, which they say taxpayers can't afford.

“The showdown in Montana lays bare a bitter ideological divide stalling the expansion of Medicaid coverage in states concentrated in the US South and central West,” writes Letitia Stein for Reuters.

Currently, 28 states and the District of Columbia have expanded Medicaid under Obamacare, and about half a dozen other states are considering whether they will also accept the billions of federal dollars available for expansion.

Debates similar to the one in Montana are playing out in Alaska and Missouri. In January, Indiana accepted Medicaid expansion, after the Obama administration agreed to give the state a waiver to charge premiums and add other market-based features.

Some state lawmakers have said the cost of Medicaid expansion is their primary concern, The Hill reported. While the federal government is pledged to pay all the initial costs through 2016, the states are expected to pick up 10 percent of the costs by 2020.

Although some moderate Republicans have decided that accepting federal funds is a smart economic move, others are taking the more hard-line approach.

On Wednesday, the GOP-controlled Nebraska Legislature voted 28 to 16 to move the issue to the bottom of its agenda, effectively killing the measure for the year. Republican Gov. Pete Ricketts wrote this week that expanding Medicaid would become an expensive burden that the state could not afford, according to the Associated Press.

Furthermore, Americans for Prosperity, a conservative political advocacy group supported by the billionaire brothers David and Charles Koch, is funding campaigns across the country that directly target Republican lawmakers who are considering Medicaid expansion. Critics say this effort put the brakes on Tennessee’s attempt to expand the program.

“[State lawmakers] were scared to death of Americans for Prosperity,” Craig Becker, president of the Tennessee Hospital Association, which supported the expansion plan, told ModernHealthcare.com.

"Tennessee is a red state, and there is a reaction to anything that is associated with Obamacare," Charlie Howorth, spokesman for the pro-expansion Coalition for a Healthy Tennessee, told Reuters.

Medicaid is, according to the Henry J. Kaiser Family Foundation, the nation’s main public health insurance program for low-income people.

Get the Monitor Stories you care about delivered to your inbox. By signing up, you agree to our Privacy Policy

In an interview with ABC News this week, President Obama encouraged states to expand the program.

“There are millions of more people that could be helped, and it won't cost the state anything," he said. "We're just seeing some stubbornness that's really based on ideology, not on wise public health policy, that is preventing most people in most states from getting the Medicaid that would save the state money in the long term.”