Defiant Edwards battles on as Dean fights for survival

John Edwards was on track for a strong second place finish in Wisconsin's primary last night, positioning himself as the last realistic challenger to John Kerry, the front-runner, as he prepared to carry his presidential candidacy forward to "Super Tuesday" on 2 March.

Early exit polls showed the North Carolina senator with about 30 per cent of the vote, compared to slightly over 40 per cent for Mr Kerry. Howard Dean, the former Vermont governor, was running a distant third with 15 per cent.

Even before the final result was in, the North Carolina senator had finalised plans for a series of fund-raisers in New York, followed by a five-state, three-day tour of key states which vote in a fortnight's time, when half of the delegates needed to win the Democratic nomination will be allocated.

Despite Mr Kerry's daunting lead Mr Edwards maintains that even after Wisconsin, three-quarters of Democratic voters across the country had not yet had a say. Most big states have yet to hold primaries, among them California, New York and Ohio, the three biggest prizes on "Super Tuesday". By contrast Mr Dean's fading campaign was in disarray, after his national campaign chairman became the second top aide to leave the campaign in a fortnight. A typically dogged and pugnacious Mr Dean vowed that whatever happened, he would continue his quest for the nomination. But if the exit poll resembles the final outcome, pressure on him to make a graceful withdrawal may become overwhelming. There was speculation he would transform his candidacy into a grassroots movement, allowing him to bow out of the formal race while keeping faith with diehard followers.

Mr Edwards' prospects are more viable, even though he remains a long shot.

Yesterday he received a boost with one poll suggesting that he had almost halved Mr Kerry's lead among Democrats nationwide, to 18 per cent from 33 per cent a week earlier.

The figures support Mr Edwards' contention that the more Democratic voters see of him, the more they like him ­ and that this will soon show up in primary results ­ but those same Democratic voters increasingly see Mr Edwards as an attractive running mate for Mr Kerry, rather than as nominee in his own right.

At every press conference he has to deal with questions on the subject, responding with a somewhat weary jest, "How about Edwards-Kerry?" But a recent poll for Time magazine found that 71 per cent very much liked the idea of Kerry-Edwards.