But critics say that while Congress might be able to regulate economic activity, it cannot regulate whether someone chooses not to buy insurance. They say that is legally labeled as "inactivity."
Experts say the issue of activity vs. inactivity is a novel question, and so far two federal judges have come to opposite conclusions. U.S. District Judge Henry Hudson, who recently struck down the individual mandate, agreed with the law's critic s that Congress has no right to regulate inactivity.
But U.S. District Court Judge George Caram Steeh of the Eastern District of Michigan, who upheld the law, scoffed at the notion that someone who doesn't participate is legall inactive. " Far from 'inactivity,'" the Judge wrote in his October 2010 decision, "by choosing to forgo insurance plaintiffs are making an economic decision to try to pay for health care services later, out of pocket, rather than now through the purchase of insurance."
The Justice Department also argues that the law is constitutional under the "necessary and proper" clause, which gives Congress the power to "make all laws which shall be necessary and proper for carrying into execution the foregoing powers."
In court papers, Justice Department lawyers say that the mandate "is a reasonable means to accomplish Congress' goal of ensuring access to affordable coverage for all Americans. It is therefore necessary and proper to the valid exercise of the Commerce Clause power."
According to Santa Clara's Joondeph, "The government is invoking the necessary and proper clause, arguing in essence that even if the individual mandate -- seen in isolation -- does not regulate interstate commerce, it is a necessary component of a broader regulatory scheme that does clearly regulate interstate commerce. "
But again Judge Hudson disagreed. In his ruling striking down the individual mandate, he said that an individual's personal decision whether to purchase -- or to decline to purchase -- health insurance from a private provider is "beyond the historical reach of the Commerce Clause." He concluded that the necessary and proper clause "does not provide a safe sanctuary."
Hudson saw the dispute as not being about regulating the business of insurance but about an individual's right to choose to participate. He echoed the argument of Virginia Attorney Gen. Kenneth Cuccinelli, who said, "This case is not about health insurance or health care, it's about liberty."
The health care law stipulates that in 2014 if an individual chooses not to buy health insurance he will be subject to a penalty to be paid as a part his annual tax return.
Supporters of the law say the mandate is also constitutionally valid under Congress' authority to use its taxing and spending power under the General Welfare Clause in Article I of the Constitution ("the Congress shall have Power To lay and collect Taxes").
But critics say that the penalty is not a tax and thus does not fall under Congress' taxing authority. They say its intended purpose is not to raise revenue but to serve as a punishment and compel individuals to enter into private commercial transactions.