WASHINGTON — The U.S. Supreme Court today declined to block a second trial over whether the University of Iowa law school improperly passed over a conservative scholar for a faculty position. The justices rejected Iowa officials’ plea to revisit a lower court ruling in favor of university employee Teresa Wagner. She alleges she was discriminated against by liberal professors because she is a Republican who previously worked for anti-abortion groups. In 2012, a jury found that the school’s former …