I never got the impression that Mitt was ever really well loved by Republicans, he was just a candidate who lost and dropped off the map. McCain had more going for him because he was a war hero and a Senator. Until Trump declared that no one who got captured could be a hero.
Always known as a "maverick" McCain stepped out of line and was kicked to the curb even on his deathbed. It's too bad about John McCain...he would have made a better Democrat than Republican.
But as far as health care goes I think we're on track to see younger people being able to buy into Medicare. One of Chuck Schumer's pet projects is allowing people 50 years old to buy in. We may see that pop up in the next two years along with improvements to Obamacare and more states buying into Medicaid. I really don't expect much to happen until after 2020 when Democrats take control again. History predicts that there will be a flurry of health care plans discussed, gains will be made, then Republicans will take control and chip them all away.
The most important issue in all this will be to insure that every detail passes muster with the strict constitutionalists. If that isn't possible then the law can't stand. Maybe our constitution simply rules out federally administered healthcare...
"Be yourself; everyone else is already taken."— Oscar Wilde