Byline: Daniel Klaidman

Presidential campaigns eventually settle into contrasting narratives of the candidates' biographies, character and ideology. The central fault line in the seemingly endless Democratic race has been change vs. experience. Hillary Clinton has argued relentlessly that her years in the White House and Senate have made her battle-hardened and best suited to be president. Barack Obama, by contrast, has questioned the value of Washington experience, contending that his wide-ranging background has imbued him with superior judgment. But the truth is that until recently, neither of them had run anything as unwieldy and unpredictable as a modern presidential ...