PENSACOLA, Fla.- Attorneys for 20 states fighting the new federal health care law say it will expand the government's powers in dangerous and unintended ways.

But U.S. District Judge Roger Vinson questioned at a hearing in Florida on Thursday how the government can halt massive changes to the health care system that have already begun.

Earlier this week, a federal judge in Virginia ruled in a separate case that citizens can't be forced to buy health insurance. That case is likely to end up before the U.S. Supreme Court...