Two members of the Heritage Foundation’s governing board resigned on Tuesday, in a sign of deepening turmoil at the conservative think tank after its president, Kevin D. Roberts, took the side of the conservative podcast host Tucker Carlson during a controversy over his friendly interview with an anti-Semite. The members, Abby Spencer Moffat and Shane McCullar, announced their resignations in a statement sent to The New York Times. Another member of the group’s board, Robert P. George, a professor at Princeton University, resigned last month. Ms. Spencer Moffat’s resignation is especially notable because she is chief executive of the Diana...