Reporters set up outside the U.S. Supreme Court on April 1. (Al Drago/Getty Images) The U.S. Supreme Court is weighing whether to overrule two of its own long-standing  legal precedents  – one about  presidential power  over federal agencies, which has been in place for over 90 years, and another about  campaign financing  by political parties. In the past 20 Supreme Court terms, about 1% of cases have overruled an earlier decision % of U.S. Supreme court cases that overturned older rulings in each 20-term period Note: While the Supreme Court was founded in 1789, it didn’t rule on its first case until 1791, and it didn’t overrule a prior decision until 1810. Source: Library of Congress and U.S. Supreme Court Database at Pennsylvania State University. PEW RESEARCH CENTER In the past 20 Supreme Court terms, about 1% of cases have overruled an earlier decision % of U.S.…