‘It’s the economy, stupid.’ James Carville’s slogan was right in 1992 – and it’s right in 2000. Despite the drama of the election’s aftermath, the crucial question is how the Democrats ended up converting Bill Clinton’s commanding lead into such a cliff-hanger.

From this side of the Atlantic, the Gore team’s strategic error seems to have been the economy. It became increasingly clear during the campaign that the Vice President’s desire to distance himself from Clinton had made it impossible for him to claim the President’s economic legacy.

Of course, the problems didn’t begin with the campaign: the American people seem to have become increasingly willing over the years to believe that the longest sustained growth since the war was a benevolent act of nature, nudged along by Alan Greenspan’s rule at the Federal Reserve Bank.

But the Democrat team passed up the chance to make the economy a central campaign issue and to identify – and identify with – the Clinton administration’s economic success. It is worth remembering, after all, that Greenspan himself praised Clinton’s early, tough decisions to cut the deficit, thus paving the way for years of low interest rates.

Instead, it looked as if the presidential campaign took prosperity for granted, focusing debate instead on how to spend the fruits of growth. But the shift from ‘tax and spend’ to ‘invest and grow’ was crucial to Clinton’s winning strategy for the New Democrats. In 2000, ‘invest and grow’ seemed to be on the back burner: the debate was ‘tax and spend’.

This is not to criticise the details of the Vice President’s voluminous policy proposals. The point instead is that what should have been the strategic foundation of the campaign – precious, hard-won, stable economic prosperity – was instead the missing piece. And I wonder whether that decision also meant that the Gore campaign was weakened in reaching out to ‘Middle America’, the crucial ‘working middle classes’ of the 1992 and 1996 victories.

I reflected on the American campaign as I waited for the results of our own by-election ‘Super Thursday’. In Preston, we fought squarely on prosperity. The final week’s by-election special edition of the Preston Rose, a miniature masterpiece of election campaign literature, featured an archetypal New Labour family: home-owners, employed (‘we work hard and we play hard’), delighted with their sons’ achievements at school and in sport, concerned about their elderly parents. The key message: ‘interest rates are as important as tax rates.’

Economic stability is no more an accident of the weather than the Tories’ devastating recessions. Getting the economy right is the first, essential condition for delivering on public services, opportunities and social inclusion.

But the presidential campaign suggests that claiming, and getting the credit for, economic success is the first, essential condition for decisive electoral victory as well.