One day this spring, over lunch in Chicago, David Axelrod offered up a concise summary of Team Obama's prevailing view about the race ahead against Mitt Romney. "We have the better candidate, and we have the better argument," Axelrod told me. "The question is just whether the externalities trip us up." For months before that and every day since, the litany of potential exogenous shocks—from the collapse of the eurozone to a hot conflict between Israel and Iran to a succession of brutal jobs reports—has kept Axelrod and his colleagues tossing and twitching in their beds at night. For all their overt confidence, the Obamans are also stone-cold paranoiacs, well aware of the iron law of politics enunciated long ago by the poet Robert Burns: "The best-laid schemes o' mice an' men / Gang aft agley." Which, for those unversed in archaic Scottish, translates roughly as "Shit happens."