First ladies of the United States have no formal power – and yet many are among the most influential people in American history. A new exhibition at the George W. Bush Presidential Center tells the stories of each first lady – from Martha Washington to Melania Trump. We talk with George W. Bush Institute Deputy Director Natalie Gonnella-Platts about the roles these women have played in American life. “First Ladies: Style of Influence” is on display through Oct. 1.