Since opening its doors in 2016, the National Museum of African American History and Culture has been one of the hottest tickets in Washington. We take a tour of the new exhibition “Watching Oprah: The Oprah Winfrey Show and American Culture” with its curator. And later in the hour, we cross the National Mall for a trip to the National Museum of the American Indian and a tour of “Americans,” an exhibition that looks at how American Indians are portrayed in popular culture.