Editor’s Note: Too often, historians have underestimated the role that Lady Bird played in Lyndon Johnson’s political life. An important new biography paints a different picture: that this politically astute woman was intimately involved in advising her husband on political strategy and the evolution of his career. Julia Sweig is the author of the highly acclaimed New York Times bestseller, Lady Bird Johnson: Hiding in Plain Sight, from which portions of this essay were adapted.