What makes this presidential election different from all other presidential elections? And different from what we expected when the year began?

First, neither party's presumptive nominee was chosen by massive support from primary voters, as John Kerry was in 2004, George W. Bush in 2000 or Bill Clinton in 1992.

That may not seem obvious in the case of John McCain, who effectively clinched the Republican nomination on Super Tuesday, Feb. 5. But look at the numbers: In January, McCain won New Hampshire 37 percent to 32 percent, South Carolina 33 to 30 percent and Florida 36 to 31 percent. On Super Tuesday, he won more than 50 percent only in states that were essentially uncontested: Connecticut, New York and New Jersey. He won Missouri by only 33 percent to 32 percent and California by only 42 percent to 35 percent, but won big delegate margins because of Republicans' winner-take-all rules.

McCain's strategy from July 2007 was to count on the other Republican candidates' strategies to fail. That was risky. But it worked. Republicans have accepted his victory because they're temperamentally inclined to fall in line and because it became obvious that he was the candidate with the best chance to win in the fall. But McCain was not really a consensus choice.

As for Barack Obama, at this writing he leads Hillary Clinton by 153 in "pledged delegates," those chosen in primaries and caucuses. But about 90 percent of this lead -- between 130 and 140 delegates -- came in caucuses, where the enthusiasm of his followers and the inexplicable failure of the Clinton campaign to mobilize hers gave him big victories.

We know from the nonbinding "beauty contest" primaries in Washington in February and in Nebraska on May 13 that Obama would have won much smaller margins in primaries in those states -- and much smaller delegate margins, thanks to the Democrats' proportional representation rules.

Democratic super-delegates, given votes in the 1980s to counterbalance the enthusiasm of left-wing caucus-goers, have instead moved toward ratifying the results of the caucuses and the paper-thin delegate edge Obama won in primary states. They may have good reasons for doing so -- fearing a Clinton loss in the general or a backlash from black voters if the first serious black candidate is rejected. But Obama, like McCain, is not the consensus choice of a large majority of Democratic primary voters.

This election is different from all others in another respect: These two presumptive nominees have no particular regional identity. John McCain was born in the Canal Zone, no longer a U.S. territory; grew up on military bases; moved to his wife's home state of Arizona and, running for Congress, noted accurately that he had lived in Hanoi longer than anywhere else. Continued...