"Citizens of the U.S. do not have a constitutionally guaranteed right to healthcare," I've heard many a conservative bleat. It is as though the Constitution is meant to be a document that outlines the few rights we are to be grudgingly guaranteed forever. That way we won't think we're entitled to all sorts of rights from the government. "These but no others!" they imagine it saying.
I do not believe this is intent of our founding document. The fact that it was made to be amended when necessary and that the first 10 amendments to the document are guarantees of rights pokes a big hole in that interpretation. It is also a very old precedent in our country that the Constitution does not create rights. It only enshrines those we are already endowed with into the rule of law. They are "inalienable rights." That then begs the question, where do these rights come from and what is the government's role in protecting them?
Government's role is to ensure that certain things exist in a society that are deemed too important and universally needed, and the pros of having options to choose from are far outweighed by the cons of not guaranteeing the existence of the thing in question. Certain rights fall into this category, obviously. So do, arguably, education, defense, and certain types of infrastructure. Religion has also made the list in many cultures, and you can understand why from one (archaic, crazy) perspective. But in ours, it did not because it did not pass the final test in the framers' minds (among other tests in some of their minds).
All but the most anarchic libertarians would argue that defense, roads, street signs, street lights, police, firemen, etc. are good to have provided by a government. Imagine if we each had to buy into a separate military, police force, or road company and they all competed with each other. It would be a mess.
So where does healthcare fall into this equation in 21st century America? It's certainly very important, perhaps 3rd in a list right after food and shelter. It's absolutely universally needed. In fact, we already pay for universal healthcare for illegal immigrants, poor people, and everyone else. We just pay extra for them to land in the emergency room because that's the first type of healthcare available to them.
The last point is where you could make a case against some types of universal healthcare. The British system, for example, being fully socialized (i.e. the public owns all the buildings and pays the doctors and nurses), does limit UK citizens choices a bit. I would still take it any day over the American excuse for a system. It's like forcing people to eat at a free buffet that's always there rather than "letting them choose" from several different restaurants they could never afford to eat at. Not a difficult choice when you're left high and dry by the latter option.
However, the two systems being debated as reform options here in the US (and the system in Germany and many other countries) do not do this. Single-payer and the "public option" still leave private healthcare providers intact. The latter option even leaves the existing insurance system intact, it just allows the government to compete with it (I think this is a far inferior option to single-payer, though). Choice is increased, but more people are brought into a more cost-effective and more socially just healthcare system. Win-win-win.
I think you could make a very strong case that the framers of the Constitution, were they writing the document in 2009, may very well have included a right to healthcare. And if we the people actually ran our representative government like we're supposed to (rather than letting corporate special interests do the dirty work against our own best interests), then such an amendment to the Constitution would quite likely be on the table or already long-ratified.