By identifying opposition to Nafta with Ross Perot, disliked by many Democrats as a dem agogue, the White House might gather enough support to win the House of Representatives vote on 17 November.
It is a high risk strategy. Mr Perot started his run for the presidency last year on the same Larry King Live show where he meets Al Gore tonight. In debates against President Bush and Bill Clinton he showed how effective he can be. 'Perot will kill Gore,' says Ed Rollins, the Republican consultant who worked for the Perot campaign last year.
By pitting the Vice-President against Mr Perot, the administration also inflates his political standing. 'They are resurrecting Perot just when the air was running out of his balloon,' says Jesse Jackson.
The calculation in the White House is nevertheless that they will gain more than they lose by targeting Mr Perot. They believe he is not as popular as he was. A USA Today/CNN/Gallup poll shows his approval rating has dropped to 44 per cent of voters, down from 66 per cent at the end of March.
The same poll shows that 46 per cent disapprove of Nafta, compared to 38 per cent who favour it. But the weakness of the anti-Nafta majority is that they are disunited, fractured between right and left. Jesse Jackson opposes it but so does Pat Buchanan, the candidate of extreme Republicanism in the primaries last year. By focusing on Mr Perot, President Clinton thinks he can exploit these divisions.
Zany behaviour by Mr Perot also makes him vulnerable. At a rally of 3,000 jubilant supporters in Tampa, Florida, on Sunday he claimed - that there was a plot to assassinate him. The attempt 'would take place in Tampa or at the debate in Washington. The organisation is a Mafia-like group in favour of the North American Free Trade Agreement.'
All this was reminiscent of 1992, when Mr Perot claimed a Republican dirty tricks squad had bugged his Dallas office and were planning to disrupt his daughter's wedding. The FBI said the tip about the assassination lacked credibility since it came from an unknown caller who spoke no English and claimed to have learned in a Mexican jail about a six-member Cuban hit-squad hired to kill Mr Perot.
Bizarre stories of assassination plots create derision in Washington but last year Mr Perot still won 19 per cent of the national vote despite leaving the race and coming back in at the last moment. Apart from his fondness for conspiracy theories, there is no sign that Mr Perot has lost his feel for what will sell politically. He is also supremely confident about his ability to beat Mr Gore. 'The masters of the universe are all looking down saying Gore will beat me because he has all those White House speech writers feeding him one-liners,' says Mr Perot. Then he adds derisively: 'Well, Har, Har, Har.'
On the other hand, during the presidential debates, both Bill Clinton and George Bush were trying to cultivate Perot voters and could not afford to confront their leader directly. Tonight Al Gore will have no such inhibition though his popularity has been sliding.
Yet these tactical manoeuvres will not allow the ad ministration to escape the unpopularity of Nafta. Mr Clin ton has opened himself to accusations of betrayal from union members, blacks and the left of the Democratic Party. If tonight's debate goes well Nafta might just squeak through the House of Representatives but the Democrats will pay a heavy political price.