He who pays the piper, calls the tune. A gov't can decide how much money they have or are willing to use to fund a national program, It already happens in Canada where we see certain services or people with certain conditions and ages no longer being covered. They can still call it a universal health care system but the gov't can change the rules.Your problem is you are so fixated on Trump you don't see the greater issue.
The fact that any President and any party can block this is a systemic issue, not a person one. And the true solution is to take away the ability of the govt to not supply healthcare to its people in a time of crisis.
And the best, easiest and cheapest way to do it is Medicare for All. Take away the ability and they can't use it as a political football.
NOTHING IS GUARANTEED. At least not indefinitely.