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Virginia's top-ranking attorney warned Monday that the federal government will be able to order Americans to "buy anything" if the state's lawsuit against the health care overhaul goes down, after a federal judge in Richmond heard arguments in the landmark case.

U.S. District Judge Henry Hudson said he will rule by the end of the year on the constitutionality of the Obama administration's health care law. The case is proceeding separately from one in Florida, where a federal judge last week allowed a multistate challenge to go forward.

The Virginia challenge is led by state Attorney General Ken Cuccinelli, who claims Congress lacks the constitutional authority to require Americans to buy health insurance or pay a penalty. He described the so-called individual mandate as "unprecedented" and warned Monday that personal "liberty" is on the line as the judge considers the case.

"If Virginia loses this fight and the federal government is allowed to cross this line, Congress will be granted virtually an unlimited power to order you to buy anything," he said. "That's not rhetoric. That's reality of the circumstances of this case."

Invoking Revolutionary War-era struggles, Cuccinelli suggested that not even the British would have attempted to force Americans to buy a product. His argument is that the federal government is attempting to "stretch" the definition of the Constitution's Commerce Clause in order to "regulate inactivity." In other words, the government wants to force Americans to buy a product and then fine those who don't buy that product -- a scenario Cuccinelli described as "non-commerce."

The insurance mandate, which takes effect in 2014, is the most contentious element of the new law and the chief issue in the state's lawsuit.

Attorneys for the state and the Justice Department disagreed during a 2 1/2-hour hearing on whether the law is constitutional under the Commerce Clause. The Obama administration argues that it has the authority to mandate the purchase of insurance, because those who refuse to buy it are making an economic decision that ends up costing taxpayers if and when they use publicly funded health care.

Supporters of the law warn that the legal challenge could upend a vital network of health benefits -- one which restricts insurance companies from dropping sick patients and denying coverage to children with pre-existing conditions, as well as sets up a system of government subsidies to help low-income Americans buy insurance.

Ron Pollack, director of Families USA, criticized Cuccinelli for seeking to strike the entire law over an objection to one provision.

"Today's argument by the Virginia attorney general represented political extremism and requested judicial activism run amok -- to the potential harm of families across America," Ron Pollack, director of Families USA, said in a written statement. "If he were to succeed, all the benefits of this legislation would be lost."

The case is likely to be decided before the one in Florida, where 20 states led by Florida Attorney General Bill McCollum are challenging the heath care law on similar grounds.

Opening arguments are set for mid-December.

The Associated Press contributed to this report.