The ink is still drying on the health care overhaul bill signed into law Tuesday by President Barack Obama, but attorneys general from 13 states have filed a lawsuit to challenge the legislation.
The lawsuit — which names the U.S. departments of Health and Human Services, Treasury and Labor — was filed immediately after the president's signing ceremony Tuesday. Attorneys general from Florida, South Carolina, Nebraska, Texas, Michigan, Utah, Pennsylvania, Alabama, South Dakota, Louisiana, Idaho, Washington and Colorado are joining in. Other GOP attorneys general may join the lawsuit later or sue separately.
The issue at the heart of the lawsuit is the constitutionality of the so-called "individual mandate," which requires most Americans to have an insurance plan or else pay a federal penalty.
The Constitution gives Congress the authority "to regulate commerce." In other words, once someone engages in commerce, the government has the power to regulate that activity.
But opponents say that the "commerce clause" does not give the government power to require an individual to buy something — especially insurance for the health of one's own body.
Some legal experts agree.
"Never in this nation's history has the commerce power been used to require a person who does nothing, to engage in economic activity," said Professor Randy Barnett of Georgetown University Law Center.
Mandating that all Americans purchase health insurance is akin to "requir[ing] every American to buy a new Chevy Impala every year," to help the automobile industry, Barnett said.
Other law scholars argue that Congress does have the power to regulate activities that have a cumulative effect on the economy.
"When uninsured people get sick, they rely on their families for financial support, go to emergency room [often passing on costs to others], or purchase over-the-counter remedies," said Professor Jack Balkin of Yale Law School. "All these effects are economic."
Because Congress believes national health care reform won't succeed unless the uninsured are brought into national risk pools, it can constitutionally regulate their activities, Balkin said.
Another legal issue being debated involves the government's taxing authority.
Supporters of the insurance requirement say that it constitutes a tax, not a personal mandate, and that the Constitution gives Congress broad power to tax.
"Challenges to tax laws succeed only when taxes directly or indirectly burden the exercise of fundamental rights, and there is no fundamental right to be uninsured," says Professor Mark Hall of Wake Forest University.
But Barnett and other opponents of the individual mandate say the tax is actually a penalty for not having insurance. It's a fine, they say, not a tax.
"On this theory any fine can be called a 'tax' and Congress can regulate anything at all," Barnett said.
The Associated Press contributed to this report.