The problem with Medicare for all, is that Medicare does not pay the full cost of health care.
The only reason our health care system has not imploded with mass bankruptcy of all hospitals, is because the hospitals and health care clinics are cost-shifting to private payers.
Meaning that as medicare underpays for care, private payers are over charged to compensate.
If you eliminated private payers, so that everyone was under Medicare, the result would be the entire health care system would go bankrupt.
The only way to then prevent that, would be to drastically increase taxes, to cover increased payments to health care.
Bernie Sanders, ridiculously claimed we could have Medicare for all, with just a 6% across the board tax hike. There is no mathematical way to make a 6% tax, enough to cover medicare for all. The only way that would work, is if Medicare continued to under pay care providers.
That is essentially saying "Doctors will keep working while going bankrupt".
Well that doesn't work.
A more realistic assessment is about 12%. This would have to be a real tax at all income levels, including the poorest of people. A tax like Social Security, which hammers the poor, as much as anyone else.
And as with all socialized systems, the system will need periodic increases in taxes as time goes one. This is true everywhere in Europe, and in Canada, and everywhere that government funded anything, is provided to the people.
Additionally, when the government runs out of money, the hospitals all close, like we saw in Venezuela, Cuba, Greece, and elsewhere.