In a 5-4 decision authored by Chief Justice John Roberts, the U.S. Supreme Court ruled today that the Patient Protection and Affordable Care Act is constitutional. The Court upheld the most controversial portion of the law — the requirement that as of 2014 all Americans must have health insurance or pay a penalty — as a valid exercise of Congress’s tax powers. The penalty, the majority held, is in fact a tax on those who do not have health insurance, as it is enforced through the tax code and assessed on Federal tax returns. In rendering this judgment, the Court…