In what is another major setback for the administration’s health-care reform agenda, a federal judge in Virginia ruled part of the Obamacare legislation unconstitutional today, noting that a mandate to buy health insurance exceeds the boundaries of Congress’ power.

The state’s Republican attorney general filed suit against the health reform law this summer along with prosecutors across the country who contested the mandate’s constitutionality. The White House has maintained that the mandate is constitutional under the Commerce Clause which allows the federal government to regulate interstate trade. District Judge Henry Hudson has now struck down that view.

Federal courts in Michigan and Virginia previously ruled differently, opining that the mandate was constitutional. In his ruling Monday, Hudson stopped short of blocking health-care reform’s implementation until a higher court acts. “The final word will undoubtedly reside with a higher court,” he wrote. Opponents of the law as well as the Justice Department expect the Supreme Court to ultimately make a ruling on the issue.

Health care reform’s assault on individual rights may be argued to exceed the mandate however. Not only would all Americans be forced to buy insurance; health insurance companies could not deny coverage to anyone. The law is further meant to drive down permissible doctors’ fees, affecting the rights of health providers.

The White House on Monday tried to downplay the significance of the Virginia ruling, point out that the full health-care reform bill does not take effect until 2014. The administration expects all challenges to the law will have worked their way through the legal system by then.