The NHS isn't "free" because we pay taxes to support it (well, I did before I became disabled) and we bitch and moan about it because we're British. Bitching and moaning is what we do, it's virtually a national sport. But whenever someone proposes getting rid of the old dear, we shout them down and boot them out of office. We're furious right now because, having campaigned on the NHS being safe with them, the bastard scum Tories are introducing which may, many years from now, lead to privatisation (we're furious with the Tories for many other reasons as well, we are having a national nightmare of buyer's remorse). We had a mini-hate for Americans a few years back when your right-wing started lying about our NHS.
You can still buy private insurance here and some do. Sometimes, they want to skip the availability lists (which means they're often seen by an NHS doctor moonlighting in his free time), some want luxurious hospitals and brand-name drugs (the NHS tends toward functionally spartan and generics to keep costs down), some just want the status symbol. Some large companies offer it as a perk for their high-level employees. But my point is that the NHS provides a "backstop", a ground-floor of service for price and to compete with that, private insurance has to offer a better service for a decent price. Which I always thought was the essence of capitalism. There's a small fee to have a prescription filled (currently about $15) but the young, old and poor are exempt from that and it's main purpose is to stop you bugging your doctor with crap that only needs a couple of asprin.
Proper single-payer universal healthcare in the USA would also mean building things. Hospitals, roads to connect them, ambulances for them to use, medical equipment to fill the hospitals with. And then all those hospitals need staffing. Yes, that means doctors but it also means paramedics, janitors, groundskeepers, canteen staff, someone to staff the newstand, receptionists, maintenence staff and I'm sure I'm missing out loads of people there. Yes, it would cost a fortune to set up an American single-payer universal system but that money only needs to be spent once (you just have to pay the comparatively small upkeep), creates stacks of new jobs and you get a shiny new health system out of it.
I deal with the NHS every week. Because I'm disabled (for reasons of both physical and mental health), I see my doctor all the time. I chose my own doctor, the same guy I've seen since I was a student. I can usually get an appointment within a couple of days with my own doctor who knows me and knows my history and knows the massive amounts of drugs I'm on. I know him quite well and he's not making millionaire money but he has a nice upper-middle-class life. New car every few years, couple of holidays a year, that kind of life.
Finally, here's a few figures for you (all either from Wiki or the CIA World Sourcebook):
Amount spent by Americans on Medicaid, Medicare and private insurance: aprox. $2.3 trillion, aprox. 45 million uninsured
NHS budget per citizen (in dollars): aprox. $2000 per citizen, per year. 0 uninsured.
Amount it would take to cover entire US population under NHS model (discounting start-up costs): aprox. $600 billion.
Amount to cover entire US population under French model (rated as world's best): aprox. $900 billion
Average tax paid by an average Briton: 22% + aprox. 9% National Insurance (our version of Social Security)
Average NHS administration overhead: aprox. 6.8% (unionised staff with pensions and benefits)
Maybe it's because I'm British but doesn't this blow anyone else's mind? We are twelve years into the twenty-first century and one of only two major political parties will nominate, for the most powerful position on earth, someone who has spent at least part of their campaign saying that women don't have a right to contraception.
We're down the rabbit hole now, folks. If they're arguing this, all formerly settled questions, everything, is now up for being debated again.