So, now that it might finally be over (or maybe close to it, possibly, perhaps), does Senator Barack Obama come out a bloody mess, or a battle-tested warrior? In recent weeks, a wiseguy consensus seems to have settled on the former: the idea that Senator Hillary Rodham Clinton has so weakened Mr. Obama in the race for the Democratic nomination — so diminished him, distracted him, exhausted him — that he could be a grievously damaged nominee. The wiseguys invoke the Republican race of 1976 and Democratic contest of 1980 as examples of what happens when candidates — Gerald Ford...