Mark Humphrey, Associated Press
In this Feb. 9, 2015 file photo, Gov. Bill Haslam delivers his annual State of the State address to the Tennessee Legislature in Nashville, Tenn.

NASHVILLE, Tenn. — Years of Republican attacks on President Barack Obama's health care law may have paid dividends at the ballot box, but they also made it much harder for GOP governors to make the case that expanding Medicaid in their states is a good idea.

In Tennessee, Gov. Bill Haslam corralled the broad support of business groups and the state's powerful health care industry for his plan to cover 280,000 low-income residents. But Haslam ended up losing out to a steady drumbeat of anti-Obama rhetoric and threats of primary challenges to Republican lawmakers who considered going along.

"We manage more hospital beds out of Nashville than anywhere in the country," Haslam marveled after the measure's defeat in the Legislature. "Huge economic forces, and we didn't move the needle."

Haslam said he was caught off guard by the level of mistrust of the federal government — and of the president in particular. That sentiment was stoked by the activism of outside groups like Americans for Prosperity, the political organization backed by billionaires Charles and David Koch.

"Once you throw Obamacare and that in, then everything gets hard," Haslam said.

Two days later, Wyoming lawmakers voted down the Medicaid proposal introduced by Republican Gov. Matt Mead, who like Haslam had cruised to re-election last fall. Mead had also made the case that his state's hospitals could no longer afford to absorb millions in uncompensated care for the uninsured without the influx of money made available by Obama's Affordable Care Act.

"The fact is, many of us don't like the ACA, including me," Mead acknowledged in his State of the State address last month. But he argued that state taxes already go toward funding the health care law and that the state should get the Medicaid money return.

A heavy strain of mistrust of federal programs contributed to the GOP-controlled state Senate voting down Mead's proposal.

Two other Republican governors' recent experiences on Medicaid expansion stand in contrast Haslam and Mead's. Indiana Gov. Mike Pence didn't need legislative approval for his deal with the federal government late last month, while newly elected Arkansas Gov. Asa Hutchinson saw his state's first-in-the-nation program using federal funds to buy private health insurance for the poor survive for another year after the Legislature reauthorized the program.

The private option had sharply divided Arkansas Republicans who had bolstered their majorities in the Legislature largely by running against Obama's health care law. The future of the program appeared in jeopardy after the election of several new lawmakers whose campaigns focused almost exclusively on ending the private option.

Hutchinson, who took office last month, had remained mum throughout his bid for governor whether he supported continuing the program that started under his Democratic predecessor. The extension cleared the three-fourths approval required in both chambers, and Hutchison praised the votes as the "right step forward" for reforming Medicaid.

Some reluctant supporters have taken heart that the measure's passage could set the stage for another fight over Medicaid expansion next year.

Twenty-eight states and the District of Columbia have agreed to expand Medicaid under the health care law since the U.S. Supreme Court ruled in 2012 that the decision was up to states and not mandatory. They include 10 expansion plans initiated by Republican governors.

In Tennessee, the demise of the Medicaid proposal has immediately given way to legislative efforts to kill Common Core education standards, another favorite target of tea party-leaning Republicans who call them a federal intrusion on states' rights.

Americans for Prosperity has derided the federal standards as "Obamacore," and Haslam — a champion of the standards — has been put on the defense over what he has called the "ruined" Common Core brand.

There was little controversy when the bipartisan governors association in 2009 helped develop the common education standards aimed at improving schools and students' competitiveness across the nation. The standards were quickly adopted by 44 states, but since then more than two dozen states have made moves to abandon them.

"With that brand, anybody who didn't like anything about what's happening in education, they'd say, 'Well, that's Common Core,'" Haslam said.

Associated Press writers Andrew DeMillo in Little Rock, Arkansas, and Ben Neary in Cheyenne, Wyoming, contributed to this report.