The business about “new and potentially vast” authority is a fig leaf. This is a substantial rollback of Congress’ regulatory powers, and the chief justice knows it. It is what Roberts has been pursuing ever since he signed up with the Federalist Society. In 2005, Sen. Barack Obama spoke in opposition to Roberts’ nomination, saying he did not trust his political philosophy on tough questions such as “whether the Commerce Clause empowers Congress to speak on those issues of broad national concern that may be only tangentially related to what is easily defined as interstate commerce.” Today, Roberts did what Obama predicted he would do.

Roberts’ genius was in pushing this health care decision through without attaching it to the coattails of an ugly, narrow partisan victory. Obama wins on policy, this time. And Roberts rewrites Congress’ power to regulate, opening the door for countless future challenges. In the long term, supporters of curtailing the federal government should be glad to have made that trade.