Some of the compromises could be achieved simply through negotiations with a Clinton administration.

One area of focus for conservatives is federal waivers to states that allow them to impose slightly different rules for their Medicaid programs, including requirements that beneficiaries of certain income levels be charged premiums.

The Obama administration has already granted a number of such waivers to GOP-run states that would not have embraced the Medicaid expansion otherwise, but conservatives hope to make such waivers easier to obtain or more widespread.

More fundamental changes to the ACA would require legislation, which would likely be harder to do. Barring a historic landslide election, power in Congress will likely be split, with Republicans in control of the House and Democrats either in control of the Senate or (at the very least) with enough votes to block legislation through filibuster.

If Trump loses as badly as current polling suggests, Republicans may be humbled enough to negotiate, but Democrats will likely feel even more emboldened to push the landmark law to the left, as Clinton has suggested she would do throughout her primary campaign against Bernie Sanders.

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

Democrats might be in a mood to compromise, however, if it is needed to save the existing parts of Obamacare.

With the exchanges threatened by the potential departures of major insurers, which claim they cannot turn a profit, the way to save the system might require a big appropriation of federal funding to increase subsidies to the exchanges, both to help consumers afford their plans and to help offset the losses that insurers are experiencing.