“The decision whether to purchase insurance or to attempt to pay for health care out of pocket is plainly economic,” Steeh wrote in a 20-page opinion. “These decisions, viewed in the aggregate, have clear and direct impacts on health care providers, taxpayers and the insured population, who ultimately pay for the care provided to those who go without insurance.”

Steeh’s ruling represents a major legal victory for the Justice Department since the decision rejects the central legal argument against the landmark health care reform bill Obama signed in March and a provision that has become a focus of popular anger on the right.