One way for Lincoln to have dealt with his best friend, I suppose, would be to say you're a horrible person, you're morally wrong, and I shun you," says NPR's Steve Inskeep. He also writes histories, and his newest book, "Differ We Must: How Lincoln Succeeded in a Divided America," takes a long hard look at Lincoln the politician: the man who went out of his way to build political consensus, even with people whose views he considered noxious. Today on Throughline, a conversation with Steve Inskeep about the contradictions of Abraham Lincoln.