A federal judge in Virginia ruled Monday afternoon that a major tenet of health reform legislation passed earlier this year — the individual mandate — violates the Constitution, a conclusion that is receiving praise from U.S. Sen. Chuck Grassley (R-Iowa).

“The nonpartisan Congressional Research Service called requiring people to buy a good or service or be penalized a ‘novel issue,’ and now a federal court has ruled it unconstitutional,” Grassley said in a statement. “The ruling is likely to be appealed, but it’s a clear signal that the constitutionality of the law, which was moved through Congress with a lot of controversy and partisanship, isn’t as certain as its supporters have argued.”

The individual mandate would require all Americans to carry health insurance or face financial penalties, though waivers or discounts would be provided for lower-income Americans. Two other lawsuits — in Michigan and Virginia — have ended with judges concluding the mandate is constitutional. A California federal judge rejected a similar lawsuit, saying the plaintiffs had no standing. Another lawsuit, filed in Florida, is still pending.

Grassley’s opinion of the health insurance mandate has morphed over time. The senator supported the individual mandate in 1993 when he proposed it as an alternative to President Bill Clinton’s health care legislation. In June 2009, Grassley told Fox News that individual mandates would foster individual responsibility, “and even Republicans believe in individual responsibility.”

“But when it comes to states requiring it for automobile insurance the principle then ought to lie the same way for health insurance,” Grassley said. “Because everybody has some health insurance cost and if you aren’t insured there aren’t free lunches.”

But by the fall of 2009, Grassley was a staunch critic of the individual mandate, saying it likely violates the 10th Amendment of the U.S. Constitution. In defending his apparent change of heart, a Grassley spokeswoman pointed out that President Barack Obama campaigned as an opponent of the individual mandate, saying during the 2008 presidential campaign, “if a mandate was the solution, we can try that to solve homelessness by mandating everybody to buy a house.”

U.S. Sen. Tom Harkin (D-Iowa) vehemently disagrees with the Virginia judge’s ruling, but said he’s confident the appellate courts and the Supreme Court will uphold the provision.

“When people seek medical care without health insurance and don’t pay for it, they aren’t ‘opting out’ of the health care market,” Harkin said in a statement. “Instead, it adds more than $1,000 per year to the premiums of American families who act responsibly by having coverage. This clearly affects interstate commerce and is thus within Congress’ power to regulate.”

The Virginia judge refused the plaintiff’s request for an injunction against the legislation’s continued implementation, and also refused to overrule anything but the individual mandate itself. The plaintiffs had hoped the judge would find that the entire health reform bill was unconstitutional.