The stakes grew even higher in the New Hampshire primary yesterday as contenders struggled to attract independent voters who could make or break a candidacy - and a new poll suggested that the right Democrat had a real chance of defeating President Bush.
History suggests that no one who has finished lower than second in this critical first primary has gone on to win the White House. The result of this one, too, will probably weed out at least one of the five surviving major candidates.
With 24 hours to go before polling, almost anything is possible. "We are within striking distance of winning," Howard Dean, the former Vermont governor and former front-runner, told a packed meeting at South New Hampshire University here. "This is a very close race and getting closer every day." The last sentiment, at least, is one with which even his opponents would agree.
Every poll shows John Kerry, the Massachusetts Senator, in the lead by between 8 and 20 per cent. But Mr Dean seems to be recovering from his debacle in Iowa, when his overheated pep talk to campaign workers raised doubts about his fitness for President.
Over the weekend, the new "kinder and gentler" Howard Dean was much in evidence, yesterday appearing for only the second time on the campaign trail with his wife Judy. The signs are that Mr Dean's support has stabilised after the post-Iowa plunge. A close three-way battle for third place is being fought between retired general Wesley Clark, and Senators Joe Lieberman of Connecticut and John Edwards of North Carolina.
The real stealth candidate may be Mr Edwards, a dazzling performer in small meetings, and whose strong second place finish in Iowa a week ago caused many voters to take a second look at him.
Hundreds are braving near-Siberian weather to attend each of his half-dozen daily campaign stops, to hear his optimistic and populist message, vowing an end to America's social and economic divisions and a restoration of the country's reputation in the world.
For Mr Lieberman, the survival of his candidacy probably depends on a good showing here in his native New England. But the biggest loser of the weekend may have been General Clark, judged to have performed indifferently in Thursday's final candidates' debate.
After Mr Kerry's shock victory in Iowa, the general's pitch as the only centrist in the field with a chance of defeating Mr Bush has lost credibility. His support has steadily fallen, seeing him slip back into the virtual three-man tie with Mr Edwards and Mr Lieberman.
But, as with all five major candidates, General Clark is drawing huge crowds at every stop. A thousand people turned out to watch Mr Kerry show his ice hockey skills on Saturday. The Dean rally here yesterday saw even overflow rooms jammed as hundreds of people had to be turned away - and that despite glacial temperatures as low as minus 20C.
The reasons for the exceptional interest in the primary are twofold: what is by common consent the strongest field of contenders in decades, and the all-consuming desire of ordinary Democrats to drive George Bush from the White House.
As a result, unusually large numbers of voters are undecided, checking out candidates repeatedly in the search for the one with the best chance of defeating Mr Bush. A new poll in today's Newsweek magazine suggests that man may be Mr Kerry.
Its findings, that 52 per cent of voters believe the current President does not deserve a second term, have given fresh heart to Democrats across the country. Mr Bush's approval ratings, having jumped in the wake of the capture last month of Saddam Hussein, have fallen back to only 50 per cent.
Moreover, after the resignation of David Kay, chief of the US-led team hunting for Saddam's illicit weapons in Iraq, the row over the administration's alleged pre-war exaggeration of the threat posed by Iraq is bound to grow, bringing only damage to the White House and raising questions about whether Mr Bush took America to war on false pretences.
Against that background, the Newsweek survey finds Mr Kerry beating Mr Bush 49 per cent to 46 per cent in a head-to-head contest, with the other Democrats either in a dead heat or trailing the President. The figures were touted all weekend by the Kerry campaign, as their candidate insisted that he alone had the credentials to win the November general election.
But the registered independents allowed to vote tomorrow could upset every calculation - just as they did four years ago by turning out en masse in the Republican primary to give Senator John McCain a stunning victory over Mr Bush.
This time independents, who tend to vote for more centrist candidates, could give Mr Lieberman - who vaunts his support for the Iraq war - a boost.
Alternatively, they could give a fillip to Mr Edwards. If the North Carolina senator can secure another second place here, he will be in a perfect position as the primary season moves on to more friendly territory in the south and west - just as happened in 1992 to another southerner, Bill Clinton, whose stump style was uncannily similar to Mr Edwards's now. But a bad third place or worse could see his effort fizzle.Reuse content