In April, 1965, the leaders of India and Pakistan, nations then on the brink of war, cancelled meetings with President Lyndon Johnson, and L.B.J. thought he knew why. While flying to Texas aboard Air Force One, he huddled with his speechwriter, Dick Goodwin. “Do you know there are some disloyal Kennedy people over at the State Department who are trying to get me; that’s why they stirred things up?” Johnson asked. “I didn’t know that,” Goodwin replied.