Obama won North Carolina decisively with a 14-point margin of victory. Clinton eked out a cliffhanger win in Indiana with a margin of about 22,000 votes, less than 2 percent of the total.

Obama won big in the Tarheel State, although late polls seemed to indicate that the race was narrowing. He fell just short in Indiana, where Clinton had been expected to win easily.

And Obama succeeded after the three roughest weeks of his campaign so far, weeks in which he was forced to deal with the sideshow of his former pastor, the Rev. Jeremiah Wright, and lingering salvos charging that he is an elitist. He also was coming off a resounding defeat by Clinton in Pennsylvania.

But the win in North Carolina virtually erased the gains Clinton had made in pledged delegates and the popular vote count in Pennsylvania. And, once again, Obama demonstrated that he could attract voters from all demographic groups.

Though Clinton has vowed to soldier on in West Virginia, the next contested state, her campaign now seems futile and delusional. She would have to win 68 percent of the remaining delegates to beat Obama, a nearly impossible task. Her campaign also is broke.

This race won't be decided in the trenches but rather in the back rooms where the 270 remaining unaligned superdelegates are pondering their options. The possibility that the two remaining candidates could pummel each other until the day of the nominating convention without a chance of a resolution seems custom-made for the superdelegate option.

After the 1968 Democratic convention, party officials changed the delegate selection process to make it more reflective of the votes cast during the primary season. But some Democrats worried that the changes had gone too far, freezing out the experience and expertise of elected officials and party leaders.

Superdelegates were created by the Democratic Party in 1982 to reinject greater influence by those party officials and allow them some latitude in preventing the party from marching off a cliff. The superdelegates now are selected from among governors, congressmen, state party chairs, former presidential candidates and others.

They serve as unpledged delegates who are under no obligation to back a candidate based on primary vote totals or the number of pledged delegates earned in the primary. And, as this campaign has demonstrated, they are free to change their minds along the way.

Superdelegates now make up about 20 percent of the total number of delegates who will go to the Denver convention in August. Barring a deadlocked convention, the superdelegates almost certainly will decide the outcome of this race.

It would be surprising if superdelegates -- heretofore undecided or waiting for a reason to declare for Obama -- did not begin to surge to his side now. While they might fear alienating Clinton supporters, they also must weigh the harm to Obama, the eventual nominee, from a protracted bloodbath.

Obama has earned the nomination. Superdelegates are not going to risk taking it away from him and giving it to Clinton at this point.

Let the long -- fascinating, historic, frustrating, exciting, invigorating -- primary season come to an end.