John Kerry vowed yesterday to take his campaign for the Democratic nomination to every corner of America after his powerful performance in Tuesday's primaries, which seemed to leave Senator John Edwards of North Carolina as his last serious challenger.
The Massachusetts Senator, having convincingly won five of the seven states at stake, said: "It's a huge night. It shows strength across the country and across demographics. It's a statement by Democrats across the country that I am the candidate who can take on George Bush and beat him."
The White House, too, is increasingly behaving as if Mr Kerry will be the President's opponent in November's general election, even though barely 10 per cent of the delegates to July's Democratic convention in Boston have yet been assigned.
Democrats are already drawing contrasts between Mr Kerry's record as a decorated Vietnam war hero and Mr Bush's service in the Texas National Guard, when - claimed Terry McAuliffe, the Democratic party chairman - he "went AWOL" to help on a political campaign in Alabama.
The White House spokesman, abandoning all pretence of keeping Mr Bush above the fray, described the suggestion as "outrageous and baseless". But Mr Kerry kept up the attack, implying that Mr Bush was a draft dodger.
Though Mr Kerry scored impressive wins in Missouri, Arizona, Delaware, New Mexico and North Dakota, he fell short of the seven-state sweep that would almost certainly have sealed the nomination there and then. Instead, Mr Edwards did the minimum required to keep his effort alive, by scoring a comfortable victory in South Carolina, his state of birth, and added a very close second place behind retired General Wesley Clark in Oklahoma.
That razor-thin win, in turn, keeps General Clark's campaign alive, albeit barely. But, in politics, victory by a single vote is victory nonetheless. As the former Nato supreme commander pointed out afterwards, close to tears, it was the first political election he has ever won.
But Tuesday proved predictably fatal for Senator Joe Lieberman of Connecticut, the most conservative Democrat in the field, whose slender hopes depended on a strong performance in Delaware. He managed only a second-place tie. Mr Lieberman, within minutes of the first returns, had announced his withdrawal from the race. Mr Kerry is now the overwhelming favourite; and candidates rarely fail to win the nomination after so many early victories.
Mr Edwards will expect to do well in Virginia and Tennessee, which hold their primaries on Tuesday.
But Saturday's caucuses in Michigan and Washington state may be even more important for Mr Edwards, who must show he can win outside his native South.
Michigan, the first of the old northern industrial states to enter the fray, looks a near certainty for Mr Kerry. In Washington, Mr Edwards must also contend with Howard Dean, desperately searching for a win to resurrect his collapsing candidacy. Unbowed by his failure to finish higher than third anywhere on Tuesday, the former Vermont governor is betting all on Washington and Wisconsin, which holds its primary on 17 February. These, Mr Dean desperately hopes, will serve as springboards for a comeback ahead of "Super Tuesday" on 2 March, when a quarter of the 4,317 convention delegates are allocated.
But for all his vows to go on to the bitter end, both time and money are running out for the one-time front-runner. If, as seems likely, he loses in all four states which vote in the next five days, the pressure on him to pull out could become overwhelming.
Realistically, analysts said, Mr Edwards alone can stop Mr Kerry but that would require wins outside his home base, prompting a change of mind among Democratic voters that he, not Mr Kerry, has the best chance of defeating Mr Bush.
The President's strategists intend to land some blows of their own very soon.
Concerned by polls showing Mr Kerry defeating Mr Bush in a hypothetical match-up, the Bush camp is already depicting their most likely opponent as "a Massachusetts liberal".
In doing so, they are reverting to the tactics which helped carry the President's father to his sweeping 1988 victory over Michael Dukakis, then the governor of Massachusetts.