I'd love free health care if it didn't cost so much.
Let's say that Moore is right, and the US pays $7,000 per year per citizen on health care. Now, let's nationalize it and, for the sake of argument, say that the government magically reduces the cost to $5,500 per citizen.
Now, instead of paying $2.1 trillion out of our own pockets, we pay an additional $1.65 trillion to the government every year. That's a tax increase for everyone, unless of course you want to levy that tax on "the rich", and thus stifle investment and growth.
Either way, that would increase the Federal government's revenue and expenses from $2.55 trillion to $4.2 trillion.
Putting an additional $1.65 trillion under Federal responsiblity is not a welcoming prospect, considering our government's track record with big ticket items. Socialized/Nationalized health care is far too expensive to implement in the United States.