A historian offers a different take.
Like the calls for Al Gore to concede the presidency to George Bush in November 2000, this anxiety about the imagined consequences of a protracted fight misreads both history and the calendar. In 2000, pundits seemed not to know that contested elections in previous years—notably the 1960 race between John F. Kennedy and Richard Nixon—remained officially unresolved until barely a month before Inauguration Day, and so they talked as if each hour of uncertainty brought the republic nearer to doom.
The calls to wrap up the Democratic primary race show a similar amnesia. To suggest that March 5 marks a late date in the calendar ignores the duration of primary seasons past. Indeed, were Hillary Clinton to have pulled out of the race this week, Obama would have actually clinched a contested race for the party’s nomination earlier than almost any other Democrat since the current primary system took shape—the sole exception being John Kerry four years ago. Fighting all the way through the primaries, in other words, is perfectly normal.