But let's take Mr Perot's advice and go to a Wal-Mart to test voter opinion, including opinion on Mr Perot's second coming.
The store stands in the dry hills and neon forests of fast-food signs in the northern suburbs of San Antonio, in southern Texas. This is Bexar (pronounced Bear) County, a key swing area in America's third most populous state, home to Mr Perot and alleged home of the President. Over 90 minutes we stop, Ancient-Mariner-like, about 50 people. Only one admits to being remotely interested in voting for Mr Perot. Richard James, 58, says: 'I guess I'll throw a coin in the air. If it comes down heads I'll vote Clinton. Tails for Bush. If it stands on its side I'll vote for Perot.'
Other Wal-Martians - buying paint-scrapers, nappies, hose- connectors, car tyres - split evenly between George Bush and Bill Clinton, with noticeably more men for George and more women for Bill. One Bush supporter concedes that the President faces the 'scrap of his life' to win his adopted home state.
Perot? Charlotte Pardee, 72, sums up this doubtless unscientific sample of 'real Americans'. 'If the little runt hadn't cut out on us the first time, I might have voted for him. I thought he might have got things moving again. Now I'm voting the straight Democratic ticket.'
One strand of conventional wisdom holds that Mr Perot, who takes part in the first presidential debate tonight, may still influence the outcome of the election in three weeks' time. He could (a) take swing votes from Mr Clinton in the Mid-West and North-east and deliver the race to President Bush; or (b) take white, middle- class votes from Mr Bush in Texas and the South and deliver a landslide to the Democrats.
The huge audience for the Perot 30-minute 'info-mercial' broadcasts last week - more than 11 million viewers for the first one - suggests the irascible billionaire is still a potent factor. But anecdotal and polling evidence in his home state implies that 'Perot II: He's Back' is attracting more curiosity than support. The difference of mood, and pace, from the first Perot campaign is notable. Many thoughtful, ordinary, intelligent, cautious people, who first flocked to the Perot banner in late spring, are gone. The survivors are the true believers and they believe he can win in Texas.
Since this seems unlikely, who is going to carry Texas on 3 November? Mr Bush, far behind in the two biggest states, California and New York, must win here to have any chance of remaining in the White House. Mr Clinton can probably afford not to win here (though no Democrat in two centuries has become president without carrying Texas).
To take Texas, either man has to win Bexar County, a majority Hispanic sprawl of leafy and gritty suburbs, with the lovely city of San Antonio (and the remains of the Alamo) at its centre. Diane Roth, vice-chair of the Bush- Quayle campaign in the state, says: 'Republicans can't win Texas unless they take Bexar County. That's an old and absolute rule.'
So it was that San Antonio became, for a few hours last week, the capital of the Americas and the scene of an electoral mugging. The White House moved the initialling of the US-Mexico-Canada Free Trade Agreement here on Wednesday. The Bush campaign hopes the hoopla will peel off part of the Democratic Mexican- American vote in southern Texas.
Mr Bush stayed on to film a television phone-in, Larry King Live. During this appearance the President, with earnest expression, suggested Mr Clinton might be less than patriotic because he visited Moscow as a 22-year-old student in 1969. The accusation - based on no evidence of wrong- doing, as Mr Bush admitted - has dominated electoral news ever since, as the President's campaign foresaw. Mr Bush then flew to Houston and complained that the campaign was getting dirty.
Republican leaders, jumpy about Texas until a few days ago, say they are feeling easier. 'Our polling shows we've gained steadily since the Republican Convention, and we've gone ahead in the last few days,' Mrs Roth said.
Clinton supporters are equally confident: they point to the anticipated high turn-out among Mexican-Americans and the discontent in the white, Wal-Mart suburbs. Lukin T Gilliland Jr, a fifth-generation Texan, is co-chair of the Clinton-Gore campaign in Bexar County. Texans, he says, feel more comfortable with the boy-from-the-next-door state than with any Democratic candidate since LBJ. 'Last year I took Clinton to one of my restaurants to meet some apolitical friends. He had them romanced off their feet, and they were the sort that never get romanced by anything less than two pitchers of beer.'
But Mr Clinton's campaign, preferring to concentrate resources elsewhere, is taking more money out of Texas than it is putting in, and the state may be slipping away from him. a Mason- Dixon poll last week - disputed by the Democrats - put Bush at 45 per cent, Clinton at 39 and Perot at 14.
The most likely outcome, a Clinton near-miss in Texas, suggests a Clinton victory nationwide. But the dimensions of that victory may be smaller than more optimistic Democrats expect.