Kerry in command

Sen. John Kerry has bolstered his position as the dominant front-runner in the race for the Democratic nomination, even as several of his rivals gained new sparks of life that could foretell a longer - and possibly more competitive - contest to come.

By winning 5 of 7 states - and the majority of the delegates - in a series of primaries and caucuses spread across the South and West on Tuesday, Senator Kerry has proven that he can win outside the Frost Belt and draw support among a variety of key Democratic constituencies, including African Americans.

But his achievement was tempered by Senator Edwards's win in South Carolina and retired Gen. Wesley Clark's narrow victory in Oklahoma (with Edwards posting an unexpectedly strong second-place finish there), allowing both men to remain in the race and try to position themselves as credible alternatives to Kerry.

Tuesday's contests did have a winnowing effect: Sen. Joseph Lieberman, who failed to win anywhere, ended his presidential bid late Tuesday night. On the other hand, former Vermont Gov. Howard Dean, who also failed to win a single state, vowed to press on, looking ahead to primaries and caucuses this weekend and beyond.

But while Kerry may not have gotten the "clean sweep" victory that would have all but ended the race, the continuing presence of so many rivals could ultimately work to his advantage, by preventing the emergence of a single opponent - such as Edwards - who could turn the race into a more competitive two-person battle.

"It was a good night, but not a perfect night, for Kerry," says Bruce Cain, a political scientist at the University of California at Berkeley. "He would have liked to have obliterated everyone else."

Kerry won handily in Arizona, Missouri, Delaware, North Dakota, and New Mexico. Exit polls showed he was a top choice among voters who cared about experience, and among those concerned about a candidate's ability to beat President Bush in November.

Still, some of Tuesday's results hint at a lingering fluidity. Kerry was not able to win in either of the Southern contests - a factor his rivals will likely cite as a weakness for a general-election candidate. In South Carolina, Edwards beat Kerry among voters who cared most about the economy, as well as winning handily among moderates and white voters.

The Oklahoma contest proved the most competitive of the night, with Clark and Edwards winding up in a statistical tie, and Kerry not far behind.

"The majority of the voters are split all over the place," says Bob Darcy, a political scientist at Oklahoma State University. There's no real consensus yet, and Oklahoma was no exception, he notes.

Certainly, next week's primaries in Tennessee and Virginia now become far more critical - offering both Edwards and Clark a chance to build on their wins, and presenting Kerry with another opportunity to show he can compete in the South. The Kerry campaign is reportedly buying advertising time in both states, possibly at the expense of some of the contests that come this weekend, in Michigan (where Kerry has a commanding lead in polls), Washington, and Maine.

Yet Kerry points out that he's the only candidate running a credible national campaign, while Edwards and Clark still have the far harder task of proving they can win outside their native regions. And the Democratic establishment is showing increasing signs of closing ranks behind Kerry - a factor that could tilt the balance more heavily toward him in days to come.

Indeed, analysts say it may become increasingly difficult for any of Kerry's cash-strapped rivals to topple him in the kind of TV-and-tarmac campaign the race is heading into in the big states to come.

"It's hard to imagine that things aren't going to consolidate behind Kerry," says Floyd Ciruli, a Denver-based pollster.

In many ways, the 2004 Democratic battle is beginning to echo elements of the nomination contest in 1988. That year, another well-funded Massachusetts favorite son, Michael Dukakis, won most of the early primaries and drew the broadest support among Democrats geographically. But the race was prolonged by rival Al Gore, who won a few Southern primaries, though ultimately wasn't able to take his campaign beyond the region. A wild card was the Rev. Jesse Jackson, who stayed in the race accruing delegates all the way to the convention - a role that may be played by Dr. Dean this year.

But Kerry has certain advantages that Dukakis did not. He won in both Iowa and New Hampshire, a rare feat for a non-incumbent. (Dukakis won New Hampshire, but not Iowa.) The primary process is more frontloaded than ever before, with five more contests in the next week. Kerry may also benefit from a Democratic Party that is strikingly unified in its desire to beat Mr. Bush - leading many voters to want to choose a nominee quickly, rather than prolonging the primary process.

• Staff writer Josh Burek contributed to this report.