Franklin Delano Roosevelt loved to keep secrets. He didn't want the public to know he was bound to a wheelchair, so he went to elaborate lengths to hide his inability to walk on his own. And when he was dying, his doctors hid it from the public. Even Roosevelt himself didn't want to know. Secrets of a different sort lie at the heart of two new books about Roosevelt the candidate and Roosevelt the president, with a special guest appearance by Adolf Hitler, before he became der fuehrer. David Pietrusza's 1932: The Rise of Hitler and FDR--Two Tales of Politics,...