With Donald Trump's presidential campaign faltering, Republican health policy experts are gaming out Plan B for working with a Hillary Clinton administration to achieve conservative health care goals.

Their focus is on a possible “grand bargain” that would give conservative states greater flexibility to design market-based approaches to make coverage more affordable and reduce spending in exchange for covering low-income workers in non-Medicaid expansion states. A key element, conservative experts say, would be for a Clinton administration to make it easier for states to obtain Section 1332 waivers under the Affordable Care Act. Those waivers allow states to replace the law's insurance exchange structure with their own innovative models.

While none are ready to sign on yet, congressional Republicans would have to agree to shore up the ACA's struggling exchange markets by paying insurers for enrolling sicker populations and continuing to help low-income enrollees' with cost-sharing responsibilities. House Republicans are challenging the cost-sharing subsidies in court.

Even after losing the White House, GOP leaders would have leverage because the exchange markets are experiencing major problems. Democratic presidential nominee Clinton, who has promised to expand coverage and improve affordability under the law, will need to make those markets financially viable for insurers by increasing enrollment of younger and healthier Americans.

Both Republican and Democratic observers say compromise remains a long shot. The GOP would have to set aside its repeal-or-bust stance on the ACA. Ms. Clinton would have to risk alienating her party's left wing, which backed single-payer insurance coverage during the primaries.

Still, “the chances of a deal are higher than they've been,” said Gail Wilensky, a veteran health economist who was Medicare administrator under President George H.W. Bush.

“It might be easier (to cut a deal) if Clinton is president,” said John Goodman, a conservative health policy strategist. “The problem is the Democrats can't be seen to be repealing Obamacare, and the Republicans can't be seen making Obamacare work better.”

Even if Republicans lose the Senate, a President Clinton would face continued opposition in the House, which is likely to stay under GOP control. But she would have administrative leeway to give states Section 1332 waivers. “There may be some areas where Clinton could make some progress, but it would be tweaks here and there,” said Lawrence Jacobs, a liberal-leaning expert on health care politics at the University of Minnesota.

Allowing red states to tinker with Medicaid — forcing low-income residents to make small contributions, for instance — will run into strong resistance from the left.

Ms. Wilensky said Clinton could score points with Republicans by relaxing the Obama administration's guidance on the 1332 waivers that restricts states' ability to integrate their exchange and Medicaid markets. That would enable lower-income people to maintain plan and provider continuity as their income fluctuates.

To win GOP backing for measures to stabilize the exchanges, Republicans will seek changes to make ACA coverage more attractive and affordable for younger people, said James Capretta, a conservative health policy expert at the American Enterprise Institute. That includes allowing lower premiums for young people, a wider range of benefit designs and premium subsidies for plans bought outside the exchanges and easing minimum benefit requirements.

Ms. Clinton's best opportunity might be to persuade GOP governors and lawmakers in non-expansion states to accept Medicaid expansion by giving them more leeway on program design. “There is potential for a deal if … we can all agree to let blue and red states try things and learn from experiments on both sides,” said Joel Ario, managing director of Manatt Health and a former CMS official under President Obama.

Ms. Wilensky is guardedly optimistic about bipartisan cooperation on health system improvement if Ms. Clinton wins and Republicans retain at least some control of Congress. “I hope people are getting a little tired of the standoff,” she said.

Harris Meyer writes for Modern Healthcare, a sister publication of Business Insurance.