From the dissent:
That clear principle carries the day here. The striking case of Wickard v. Filburn, 317 U. S. 111 (1942), which held that the economic activity of growing wheat, even for one's own consumption, affected commerce sufficiently that it could be regulated, always has been regarded as the ne plus ultra of expansive Commerce Clause jurisprudence. To go beyond that, and to say the failure to grow wheat (which is not an economic activity, or any activity at all) nonetheless affects commerce and therefore can be federally regulated, is to make mere breathing in and out the basis for federal prescription and to extend federal power to virtually all human activity.
From now on, everything you do, or do not do, can be regulated by the Federal Government.
The Government was invited, at oral argument, to suggest what federal controls over private conduct (other than those explicitly prohibited by the Bill of Rights or other constitutional controls) could not be justified as necessary and proper for the carrying out of a general regulatory scheme. … It was unable to name any.
If the concern is that the uninsured impose costs on the rest of the country, the solution is for them to bear the cost of their decisions while opening up the health insurance market for competition.
Do you ride a bicycle? That increases your risk of injury. Since everyone else pays for your injuries, the Federal Government now has the power to regulate whether, when, and how, and which bicycles you may ride, anywhere, even on your own property.
In fact, the Federal Government's bureaucrats now have the power to decide whether your life is worth enough to keep you living for an extra few days, or be able to walk for an extra few years.
You may think the current political authority will always decide according to your wishes, but don't depend on it:
The critics of the capitalistic order always seem to believe that the socialistic system of their dreams will do precisely what they think correct. While they may not always count on becoming dictators themselves, they are hoping that the dictator will not act without first seeking their advice.
They forget that a dictator, too, may act differently from their wishes, and that there is no assurance that he will really try for the "best," and, even if he should seek it, that he should find the way to the "best."
This decision serves no other purpose than to strengthen the argument that everyone who supports it must be replaced in the next election so that there is a fighting chance to implement solutions in health care financing that do not depend on intricate central planning bureaucracies.
… the Framers considered structural protections of freedom the most important ones, for which reason they alone were embodied in the original Constitution and not left to later amendment. The fragmentation of power produced by the structure of our Government is central to liberty, and when we destroy it, we place liberty at peril. Today's decision should have vindicated, should have taught, this truth; instead, our judgment today has disregarded it. (emphasis mine)