Elspeth Rostow, the Stiles Professor Emerita in American Studies and a Professor of Government at the Lyndon B. Johnson School of Public Affairs, served on multiple boards and commissions under Presidents Carter and Reagan. In this video clip, she discusses the growth of presidential power in the area of foreign policy in the twentieth century. She notes how public support increases a president's ability to exercise the war powers - if the president can secure and maintain such support.