The U.S. Supreme Court decided many weighty issues this year, from striking down much of Arizona’s controversial immigration law to ruling that GPS surveillance of cars constitutes a search under the Fourth Amendment. But none were as consequential as the decision to uphold most of President Obama’s landmark health care reform law known as the Affordable Care Act. The decisive — and politically controversial — majority opinion, crafted by 57-year-old Chief Justice John Roberts alone, carved a narrow path between the positions of the liberal wing and Roberts’ conservative colleagues. Requiring people to buy health insurance would be unconstitutional, Roberts wrote, but asking those without insurance to pay a penalty is no different than a tax and therefore constitutional. Millions of uninsured Americans will buy coverage in 2014 because of Roberts’ judicial agility, which, combined with Obama’s re-election, has left even strident opponents like House speaker John Boehner reluctantly conceding that the GOP crusade to repeal Obamacare is over.