WASHINGTON - Every Tuesday has been good for John Kerry this primary season. This one was super.

With a string of smashing primary victories, the Massachusetts senator transformed himself from Democratic front-runner to nominee-in-waiting of a party united in its desire to defeat President George W. Bush.

Even before the polls closed in California, Senator John Edwards' decision to withdraw from the race signaled the end of the nominating campaign.

Bush himself said so, calling Kerry for a ceremonial touching of the gloves ahead of what figures to be a bruising eight-month general election campaign.

"He called to congratulate me. I said I hope we have a great debate about the issues before the country," said Kerry, whose campaign calling card of electability helped him win all but two of 30 contests over a period of six weeks.

He commented at an election-night party in downtown Washington. Not that there will be much time for celebration.

On Thursday, Bush's re-election campaign dips into a US$100 million-plus war chest to begin television commercials in 50 or more cities across more than a dozen battleground states. It's money that Kerry doesn't have - in states where he hasn't yet polled for a general election contest.

For now, at least, the ads will be designed to shore up Bush's image, to depict him as a leader who has made the country safer in the wake of terrorist attacks and helped put the economy back on track. Later, there will be more detailed talk of an agenda for the future.

For Republicans, there's also plenty of time - and money - for attacks meant to define Kerry as a liberal senator from Massachusetts who talks one way, votes another and possesses a record out of step with independents who will decide the election.

"We have some air clearing to do," said Terry Holt, press spokesman for Bush's re-election campaign.

"John Kerry came through this (primary) process relatively unscathed. He has high name identification, but very soft. It's a mile wide and an inch deep," he said.

Kerry, who leads in the national public opinion polls, says he won't be a "wishy-washy, mealy-mouthed" Democrat, when it comes to the fall campaign.

"The president's record tells it all," said spokeswoman Stephanie Cutter. "Just as Republicans want to run on Bush's record, so do we. Three million jobs lost, 40 million (who) lost health care, and the nation is less secure. The American people are ready for change."

In all, California, Connecticut, Georgia, Massachusetts, Maryland, New York, Ohio, Rhode Island and Vermont held primaries on the busiest day of the campaign season, Super Tuesday. There were caucuses in Minnesota.

The primary campaign has been quick and polite by historical standards. In exit polls Tuesday night, voters said a candidate's ability to defeat Bush was their top concern.

That's not surprising for a party out of power in the White House and both houses of Congress for the first time in more than four decades.

The kick-off Iowa caucuses were held a scant six weeks ago. And when Iowa Democrats punished the two men who had sharply criticized one another - elevating Kerry and Edwards over Howard Dean and Dick Gephardt - the clear message was that campaign attacks were to be reserved for Bush, not spent on one another.

The quick calendar was by design, worked out in advance by Democratic chairman Terence McAuliffe with the candidates to give the winner plenty of time to regroup for the general election campaign.

"If we were fighting all the way through May, we wouldn't be able to have television advertising and we really would have had US$40 million or US$50 million worth of advertising bombarding us from the other side," the party chairman said in an interview.

Each party is permitted to spend US$15 million or slightly more in direct assistance to its nominee, and unlike four years ago, Democrats say they have the money.

That's good for Kerry, who began February with slightly more than US$2 million cash on hand, with debts of US$7.2 million.

Exit polls in several earlier primary states showed that Kerry benefited from the perception that he would be best able to lead the party to victory in the fall.

(Agencies via Xinhua)