Health care, like any good/service, has to be produced which means scarce resources must be used in its provision. Does anyone have a right to scarce resources? To say that someone has a right to health care means that someone has a right to use a scarce resource despite its opportunity cost. In short, it means taking away someone else's liberty.
"Defenders of positive liberty say that there is no need for it to have such totalitarian undertones. ... For example, if the state asks the citizens what they want instead of making that decision for them, positive liberty can be guaranteed without any hint of totalitarianism."
Aside from deciding whether people have a right to health care, what is health care in the first place? Most surely it would include treatments for cancer and cardiac surgery, but would it also include taking an aspirin for a common headache or putting on a band aid after skinning one's knees? Would it include taking an aspirin to stave off heart disease?
With nationalized health care, the answers to these questions are put into the hands of bureaucrats who have little or no regard for the people (and these people's property) they oversee and the people have little recourse than to abide by their deicisons. In other words, its dictatorial at its core.
Via Instapundit