The deadline for President Obama to secure congressional authorization for the military operation in Libya went whizzing by Friday without such a vote, fueling lawmakers' concerns that the administration was flouting the law, but the White House insisted it was on solid legal footing. The concerns stem from provisions in the 1973 War Powers Resolution. The resolution, passed in defiance of then-President Nixon at the tail end of the Vietnam War, states that presidents must seek congressional approval to keep U.S. forces in hostilities for more than two months. Friday was the 60th day of U.S. involvement in the U.N.-backed...