In the end, it was odd man out: Ross Perot lacked the political instincts required to reach the White House. But he has proved that Americans are ready for real change, says Rupert Cornwell

Whatever else may be said about Ross Perot, at least he went out with a bang. No gradual slide to insignificance by polling day for him. Instead, a never-declared candidate who briefly seemed to pose the greatest threat to America's established two-party system in 80 years has dramatically folded his hand, before the battle was even joined in earnest.

In all, Mr Perot's adventure lasted less than five months. But its traces have been profound. Although America will have a conventional two-horse race this autumn, its outcome will be shaped by the millions of ordinary voters who briefly worshipped a man from Dallas they hardly knew.

Among the wise and the weary in Washington, hardly a soul took it seriously when Mr Perot confided on 20 February to a Cable News Network talk-show host that he would be prepared to run for president if supporters placed his name on the ballot in all 50 states. As is so often the case, though, the wise and the weary were wrong. Within weeks, a popular movement had caught fire the likes of which the US has never seen. By May, Mr Perot was leading both Governor Bill Clinton and President George Bush. A disillusioned country seemed poised to reject its entire political system.

Now, no less suddenly, the bubble has burst. By the end of June he had fallen back to equality with his rivals; in the last 10 days he had clearly slipped behind them. But no one thought his demise would be so swift, in a year of shallow loyalties and violently fluctuating polls. So why has he withdrawn, leaving millions of supporters the length and breadth of the country - if yesterday's first reactions are to be believed - grief-stricken, bewildered and betrayed?

The immediate answer lies in Mr Perot's character. His career has been a history of all-or-nothing, from his tempestuous, unsuccessful bid, in the mid-Eighties, to overhaul General Motors, to his obsession with missing American prisoners of war in Vietnam. The businessman in him spoke: why throw good money after bad? Already he had invested dollars 10m in his campaign: why waste the rest of the dollars 100m he was once ready to spend?

More fundamentally, however, Mr Perot, for all his ability to inspire, was by temperament simply not a politician, lacking the patience, the judgement and the skills of compromise and coalition-building that are the essential components of the trade. The departure of his campaign co-chairman Ed Rollins on Wednesday was one ominous sign; another was a disastrous appearance before black leaders last weekend. The unwittingly offensive tone of his remarks showed that Mr Perot simply had not done his homework.

Most important of all, he would not listen. At huge cost, he hired advisers brought in from Washington but would not heed their insistence that he quickly move from sound-bites to specifics. At first, the twangy Texan exhortations to 'get under the hood and fix the engine' sounded fine. To preach change is one thing: there comes a moment when a politician must set out how to achieve it. But Mr Perot, as he loved to proclaim, was not a politician.

He believed mere symbolism was enough, that the very fact of his crusade would draw the best and the brightest of both parties to his side. While Mr Rollins and others implored him to launch an advertising campaign to establish a firm identity with voters, the man from Dallas thought he knew better.

As a result, he was utterly ill-equipped to react when the honeymoon period drew to a close and his record - as it had to - came under genuine scrutiny. A truly professional political campaign, like Mr Clinton's in the dark days of New Hampshire last January, would have swiftly developed a strategy. Policies would have been set out, television screens would have been saturated with his picture. A decline in the polls could have been arrested. But Mr Perot had nothing to fall back on. As the Democrats have found their second wind, voters have taken a closer look at Mr Perot - and found an empty vessel.

Of course, the Republican attacks against him, the media probing of his past business activities and the 'Inspector Perot' image that emerged of a man given to private sleuthing of his foes damaged him. Compared to what Mr Clinton has endured, they were little more than pin-pricks. But the can-do, all-action businessman simply had no stomach for a prolonged fight he had scant chance of winning. Maybe, Americans will come to think, politicians are not that bad after all. At least they are not quitters.

And there is perhaps another lesson, obscured throughout Mr Perot's dazzling ascent. On paper, no third party candidate in US history was better armed. He had limitless money of his own, a reservoir of disgust with politics-as-usual to draw upon and a proven record of achievement. The early adulation was certainly overdone: but the extraordinary collapse of his campaign only proves how difficult it will be for an independent, without an existing party base, to make it to the White House.

In retrospect, the turning point was probably at the start of June, when Mr Perot enlisted, amid much fanfare, the services of Mr Rollins and Hamilton Jordan, another of the most skilful political strategists in the land. At that moment, his problems began. A grassroots movement could not adjust to playing politics by the normal rules. The 'world-class campaign' that the Dallas billionaire promised degenerated into a feud between the volunteer activists and the experts. Instinctively, Mr Perot sided with the former, who would not argue with him. But he needed the latter.

Sooner or later, an independent candidate has to demonstrate that he or she can put together a credible government. No real heavyweight rallied to the Perot banner: the best known, the former arms control negotiator Paul Nitze, walked out last weekend after a row over foreign policy. Mr Perot was not making much progress in his search for a vice-presidential running mate, another crucial pointer to his chances of a smooth takeover in Washington. Mr Clinton's acclaimed choice of Senator Al Gore has served to bring home the advantages enjoyed by the established parties.

But however imperfect, the five-month presidential adventure of an autocratic Texan has served the US well. Republicans and Democrats alike have been shaken out of their complacency. Mr Perot has proved that the country wants real change. America has been spared the paralysing prospect of a deadlocked, three-way election whose result would have been messily settled in the House of Representatives. Mr Bush and Mr Clinton have been warned. Whichever of them wins on 3 November knows he must deliver. The voters Mr Perot briefly mobilised this time will be around in 1996. Just conceivably, if all goes wrong, another outsider, possessing better political instincts than Mr Perot, might enter the race and not pull out after a mere five months.

(Photographs omitted)