Republicans suffered a serious split in 1964; Democrats fell apart in 1968 and 1972. Substance caused the ruptures. Significant differences separated Goldwater conservatives and the GOP's Northeastern establishment; significant differences separated mainstream liberals and the New Left. The contest between Barack Obama and Hillary Clinton lacks similar magnitude.

It has drama, to be sure, but where is the substance and intellectual heft? This is a campaign not about ideas and direction but about character, personality, and boilerplate. The Obama and Clinton platforms differ not in emphasis but primarily in degree.

Tuesday's primaries in Indiana and North Carolina all but ensure that Obama will be the Democratic nominee. It probably would take satanic intervention to deny him the party's nod in Denver. Nevertheless, Clinton persists. Why?

Perhaps to continue to raise money so her campaign can repay the considerable sums she has lent it. Or, as guessperts suggest, she might be trying to force herself on the ticket as the vice-presidential candidate. Does she think Obama is nuts?