You hear sometimes that, now that we know the sordid details of the lives of some of our leading figures, America has no heroes left. When I was writing a book about the Wounded Knee Massacre, where heroism was pretty thin on the ground, I gave that a lot of thought. And I came to believe that heroism is neither being perfect, nor doing something spectacular. In fact, it’s just the opposite: it’s regular, flawed human beings, choosing to put others before themselves, even at great cost, even if no one will ever know, even as they realize the walls might be closing in around them.