Sen. John Kerry’s (Mass.) strong showing on Tuesday, during which he won five of seven contests and added 128 delegates to his total, solidified his position as the Democratic presidential frontrunner, demonstrating once again the importance of momentum in elections. [IMGCAP(1)]

Kerry was running a pathetic third in New Hampshire shortly before the Iowa caucuses crowned him the Democratic frontrunner. Suddenly, his poll numbers exploded in the Granite State, the Feb. 3 states and nationally as he started to take on the look of a winner.

Efforts by Sen. John Edwards (N.C.) and retired Gen. Wesley Clark to stop the Kerry bandwagon probably were not enough. Edwards carried South Carolina comfortably and performed well in Missouri and Oklahoma, adding 61 delegates to his total.

Clark nosed past the North Carolina Senator for a photo finish in Oklahoma, and had credible showings in the two Southwestern states and in North Dakota. He picked up 49 delegates.

Edwards said that he needed to win in the Palmetto State, and he did. But while the South Carolina native’s victory there helped him avoid elimination, it didn’t put him close to an even footing with Kerry.

Even if you concede Edwards much of the South, Kerry’s broad acceptability in the party and multiple victories on Tuesday demonstrate why he has the potential to sweep the early March primaries.

Clark’s showing doesn’t do much to resurrect a campaign that hasn’t really gotten off the ground. His performance apparently was strong enough to keep him in the race for at least another week, which is not the best of news for Edwards.

Edwards and Clark are still fighting to emerge as “the alternative” to Kerry. But becoming the alternative to Kerry isn’t the same as becoming the alternative to Howard Dean.

While Edwards and Clark have each won one state and placed second in three, the states where Edwards ran well (which include Iowa, Missouri and South Carolina) are generally larger or more significant politically than those where Clark ran best.

Which brings us to Dean. His strategy of bypassing the Feb. 3 states is understandable, and that is exactly the problem.

His campaign is out of gas, and he had to write off Tuesday’s states because he knew he would not do well in most of them. He won seven delegates (from just two states), not an enviable showing for a candidate who just a month ago was running the most “national” campaign and who keeps insisting that the race is all about “collecting delegates.”

Dean keeps losing, so he moves his main targets (now Washington, Michigan and Wisconsin) further into the future as a way to keep his campaign alive. But he isn’t likely to resuscitate an ailing effort that has wasted cash and failed to prevail in even one of the race’s first nine contests.

Indeed, after nine caucuses and primaries, the former Vermont governor has just one second place finish to his credit, as well as five thirds, a fourth and two fifths. Dean’s candidacy surely has set a new standard for the political implosion.

Kerry is now winning with Dean’s message, making it hard to see why Democrats in upcoming primary and caucus states would suddenly swing back to the former Vermont governor.

The Massachusetts Senator isn’t winning because voters are focusing on the candidates in great detail, but because of momentum, and his two victories have created an impression of inevitability in his nomination. Iowa and New Hampshire gave him the seal of approval, and a majority of voters who participated on Tuesday saw no reason to disagree.

Buyer’s remorse may well kick in for the Democrats later this year, but probably not until Kerry has most of the delegates he needs for the nomination.

So where does that leave the other Democrats who have been in the race?

Thankfully, Sen. Joe Lieberman (Conn.) has accepted the reality of the situation and exited the race. A serious man with a reputation for integrity, he was never a credible contender for the Democratic nomination.

The Rev. Al Sharpton and Rep. Dennis Kucinich (Ohio) are running to make a point, not to win the Democratic nomination. They’ve had their chances to lay out their plans and to make their arguments. Now it’s time for them to fade away or, if they won’t, to be ignored by the national media.

Kerry continues to have momentum, while Edwards and Clark look for opportunities to defeat him and change the dynamics of the race. But defeating Kerry in Virginia and Tennessee won’t be enough. Unless the Democratic contest takes a dramatic new turn in the next few weeks, Kerry should lock up his party’s nomination sometime on or before March 2.

Stuart Rothenberg is editor of the Rothenberg Political Report.