Argument: Insurance mandates set dangerous precedent for federal power
The Congressional Budget Office acknowledged the unprecedented nature of an individual mandate when assessing the Clinton health care reform proposal of 1993: “A mandate requiring all individuals to purchase health insurance would be an unprecedented form of federal action. The government has never required people to buy any good or service as a condition of lawful residence in the United States. An individual mandate has two features that, in combination, make it unique. First, it would impose a duty on individuals as members of society. Second, it would require people to purchase a specific service that would have to be heavily regulated by the federal government." - Hartman, Robert and van de Water, Paul, “The Budgetary Treatment of an Individual Mandate to Buy Health Insurance,” Congressional Budget Office memorandum, August 1994.
Erwin Chemerinsky. The Federalist Society Online Debate Series: Individual Health Care Insurance Mandate Debate. November 3, 2009 November 6th, 2009: "Indeed, the vertical separation of powers, under which the federal government possesses limited and enumerated powers, while the States wield general police powers, is the key part of our constitutional architecture. Far from being an 18th century affectation, these structural limitations on government powers were designed to protect individual liberty. In the Framers' view, these structural limitations on the ability of the federal government to exercise authority were the primary ways of ensuring that no single government entity would grow too powerful. They were viewed by the Framers as the most important way of protecting liberty, far more important than even the provisions of the Bill of Rights. [...] Professor Chemerinsky's vision of a Commerce Clause on steroids would fundamentally warp our constitutional architecture. Because every single decision by individual Americans, be it buying health insurance, cars, health club memberships or any other good or service, has some impact on the economy, it could be subject to regulation by Congress. Indeed, Congress would be able to compel how individuals would dispose of every penny of whatever monies they have left after paying taxes, transforming Americans into virtual serfs."
Michael Tanner. "Individual Mandates for Health Insurance: Slippery Slope to National Healthcare." Cato Institute. April 5, 2006: a federal individual health insurance mandate would be “an unprecedented expansion of government power and intrusion into the American health care system.”