Republican Greg Gianforte on Friday declined to back the GOP healthcare bill that cleared the House this week, saying he would need to see a Congressional Budget Office score before making a decision.

The businessman is the GOP nominee in the May 25 special election to fill Montana's vacant House seat, and his hesitancy to endorse the American Health Care Act in a state that President Trump won by 20 percentage points shows how politically volatile the legislation could be in 2018.

"Personally, I would have liked to have seen CBO results prior to voting," Gianforte said in a telephone interview with the Washington Examiner.

House Republicans obtained a CBO score on the original version of the bill. Those results led Gianforte to oppose it. He said the AHCA did not sufficiently reduce premiums, maintain insurance protections for Americans with pre-existing medical conditions, or preserve access to care in rural areas.

Still, Gianforte insisted that he favors getting rid of former President Barack Obama's healthcare law, and looks forward to working with the Trump administration on this and other issues if he captures Montana's statewide at-large House seat.

"We need to repeal and replace Obamacare," he said. Gianforte is running against Democrat Rob Quist, a progressive from the wing of the party dominated by Sen. Bernie Sanders, I-Vt.

Karen Handel, the Republican nominee for a closely watched special election runoff in Georgia, is taking a different approach. In a statement provided to the Examiner, her campaign said that she would have voted for the AHCA in Thursday's vote if she had had the opportunity.

"Karen would have joined with the Republicans in the Georgia delegation in voting in favor of the bill. She believes that the status quo is unacceptable and that this legislation, while not perfect, represents just the first step in replacing Obamacare with patient-centered healthcare," the statement read.

Even more than the race in Montana, the contest in suburban Atlanta for the vacant 6th Congressional District is shaping up as a referendum on Trump's leadership and the Republicans' drive to partially repeal the Affordable Care Act.

The Georgia district has been in Republican hands for nearly 40 years. But Trump only defeated Hillary Clinton there by 1.5 percentage points, offering Democrats hope of an upset. Jon Ossoff, the Democratic nominee, is attempting to position himself as a centrist. He opposes the AHCA.