But, in contrast to free market purists, Trump has also promised that whatever system comes will guarantee people coverage regardless of pre-existing conditions. But how that squares with the elimination of the individual insurance mandate remains unclear. 

The central problem of the ACA has thus far been that not enough young, healthy people have signed up to make up for the many older, sicker people who have entered the ACA marketplace, resulting in many insurers leaving the marketplace or sharply hiking premiums. 

As a result, some suggest that a full repeal of the ACA will not necessarily come soon and that whatever ultimately replaces it might not be that different from the current system. 

"The idea that they're just going to wipe that money away is pretty unlikely," says Mark Rourk, an insurance analyst, in an interview with Kaiser Health News. "They don't want to be in a position of saying they're just kicking millions of people out in the street."

He adds, "It gets into a questions of semantics. Are they really repealing the act if they replace it with new legislation that has some of the same characteristics?"

In addition, while Trump embraced the classic GOP idea of turning Medicaid into a block grant program, he has generally been reluctant to endorse spending cuts on public health programs. 

"States that have expanded (Medicaid) will leave it in place," predicts Joe Reblando, a spokesman for Medicaid Health Plans of America, tells Modern Healthcare. "And given the Republican tenet of giving states more control, states that haven't expanded yet may find increased flexibility on how to do so."

Evidence that a Trump administration won't push to roll back the expansion might be foreshadowed in the similar decision of Kentucky Gov. Matt Bevin, who ran as an avowed foe of the ACA during his campaign for governor last year but ultimately opted to keep in place the expansion that his Democratic predecessor put in place after he took office.