Within a fortnight of each other, two federal judges in Virginia, relying on identical precedents and hearing carbon-copy arguments, issued diametrically opposed decisions on the constitutionality of the federal health-care overhaul.

Read side by side, the two rulings reveal strikingly divergent views of what the case is about—and suggest that the fate of the Patient Protection and Affordable Care Act of 2010 will rest on which depiction best satisfies the Supreme Court.

Both lawsuits challenged the health-care plan's foundation: the mandate that all Americans, other than those exempted for religious or other reasons, carry health insurance or pay a penalty on top of their income taxes. The plaintiffs contend the mandate exceeds Congress's constitutional power to regulate interstate commerce.

An opinion released Monday in Richmond by Judge Henry Hudson, of the U.S. District Court for the Eastern District of Virginia, immediately zeroes in on the penalty for failing to carry health coverage.

Rather than regulate commercial activity, the measure compelled individuals "to involuntarily enter the stream of commerce by purchasing a commodity in the private market," wrote Judge Hudson, a 2002 Bush appointee. "The unchecked expansion of congressional power" represented by the mandate "would invite unbridled exercise of federal police powers," he wrote in labeling it unconstitutional.