In 'Caste: The Origins of Our Discontents', Pulitzer Prize-winning journalist Isabel Wilkerson examines the laws and practices that created a bipolar caste system in the U.S. — and how the Nazis borrowed from it.Book critic Maureen Corrigan reviews two new novels: 'The Aunt Who Wouldn't Die,' and 'Blacktop Wasteland.'Since 2004, more than 2,000 American newspapers have gone out of business. 'Washington Post' media columnist Margaret Sullivan talks about the decline of local news coverage, a crisis she says is as serious as the spread of disinformation on the internet. Her new book is 'Ghosting the News: Local Journalism and the Crisis of American Democracy.'