March 26 is a day that should not require a courtesy reminder. That’s when the Supreme Court will begin hearing arguments to decide the fate of President Obama’s health care law. Some consider the legislation as significant as Medicare and Social Security. Opponents consider it a step closer to European big-government. Scholars say the only plausible way to strike down the legislation is a 5-to-4 vote divided on ideological lines. Making it even more difficult to predict an outcome, the court itself is divided on both partisan and ideological lines. The four justices appointed by Democrats are thought certain to uphold the law. Should a conservative justice give a fifth vote of support, there is a highly probable chance Chief Justice John G. Roberts will provide a sixth. Arguments will be heard over three days. A decision in the case is expected by June.