The deafening public silence of British ministers about the US election is a function not of indifference but of deliberate self-denial. As America goes to the polls today, these ministers must not be caught out by being on the wrong side, as John Major's Conservative Party was during Bill Clinton's first campaign in 1992. Especially as they cannot predict what the outcome will be when the polls finally close in what looks like being the narrowest contest since Nixon-Kennedy in 1960. Even as they root for an Al Gore victory, they brace themselves for his defeat by a man they do not know, but whose success, if it happens, will cause a period of anxious introspection as they contemplate an election of their own.

The deafening public silence of British ministers about the US election is a function not of indifference but of deliberate self-denial. As America goes to the polls today, these ministers must not be caught out by being on the wrong side, as John Major's Conservative Party was during Bill Clinton's first campaign in 1992. Especially as they cannot predict what the outcome will be when the polls finally close in what looks like being the narrowest contest since Nixon-Kennedy in 1960. Even as they root for an Al Gore victory, they brace themselves for his defeat by a man they do not know, but whose success, if it happens, will cause a period of anxious introspection as they contemplate an election of their own.

For it isn't difficult to identify the ways in which a George W Bush victory would be a blow to Tony Blair and his fellow European leaders of a centre-left that will suddenly no longer be so confident it reflects the ideological zeitgeist. You can hear a recognition of this in the sharp irritation Labour ministers privately express about Mr Gore's failure to mobilise the Clinton magic earlier in the campaign. Indeed, since New Labour always has a story to accommodate every event, that may be the one they choose to explain away Mr Gore's failure, if there is one. Mr Gore's mistake, it may try to argue, was to fall back on old Democrat bastions such as organised labour at the expense of the incumbent's tireless pursuit of Middle America. New Labour, it will be implied by some of its high priests, must not make the same mistake.

There may be something in this argument. But it can all too easily be exaggerated Whatever the subtleties, a Bush victory will have partly tapped into the anti-government sentiment embedded deep in the frontier psyche. By being "down home" and anti-Washington, the Yale-educated son of a president will have a struck a blow, however unfairly, against the idea that governments are here to help you. And that is an idea at the heart of the exceptionally close relationship between Mr Clinton and Mr Blair. It can't be repeated too often that the differences between the American and British systems - not least the independent power of Congress - are greater than the similarities. But that does not alter the fact that there will have been a debate in the US over where the balance should lie between spending and tax cuts, including tax cuts for the rich. And if Bush is elected, the tax cutters will have won.

Nor do the pessimists stop there. A Bush victory, they say, would pitch the only superpower hard up against the ethical interventionist basis of British foreign policy. Has Condoleezza Rice, Bush's foreign policy adviser, not publicly taken a dim view of "peace-keeping", hinted at a substantial disengagement in the Balkans, and suggested that it is time for the Europeans to spend more money and energy looking after their own backyard?

For all that there is real menace in this long list of propositions, the British left should take a deep breath before plunging into defeatist gloom at the prospect of a Bush victory. For a start, it isn't clear that it would be quite the unalloyed fillip to William Hague that the Conservatives would undoubtedly claim it to be. It's true that the Tory leader has sat at the feet of Mr Bush and Mr Blair doesn't know him. But some of Mr Bush's people are relatively well known to ministers here. Robin Cook recently talked at length to Colin Powell, universally tipped to be Secretary of State in a Bush administration.

Gordon Brown's vibrant interest in the US is a good deal broader than mere attachment to leading Democrats - there being no British politician who knows, for example, more about the budget-making process of the Reagan-Bush years. Peter Mandelson knows both Ms Rice and Robert Zoellick, who is likely to be another key player in a Bush foreign policy team. One sotto voce claim in London is that a Bush foreign policy team might actually be fresher and more internally cohesive than a Democrat equivalent.

Third, I'm told that recent inquiries by key Blair staff have elicited a more emollient attitude to - for example - Balkan intervention than that reportedly suggested by Ms Rice. Even allowing for a streak of wishful thinking in Whitehall, there are grounds for predicting that Mr Bush, like presidents before him, may find that even judged by strict new criteria of national self-interest, Europe, not least because of Russia, may not be so easy to disengage from.

But even supposing that the greatest fears about disengagement by a Bush administration are well-founded, the logic hardly goes with the grain of Tory Euroscepticism. There is little evidence so far that Mr Bush, who is deeply serious about Nafta, sees any usefulness in Britain sacrificing its EU allegiances for membership of it - or even that he will fundamentally disagree with his father's frequently expressed support for greater European integration. And to the extent, for example, that Mr Bush wants to see more evidence of burden sharing by the US's European allies, the more rationale there is in the European Defence Initiative, which Mr Blair has promoted and towards which Conservative spokesmen exhibit the deepest suspicion. A Bush victory, in other words, may not be that welcome to a party making Euroscepticism its unique selling point.

And that's not all. It may be too much to say that tomorrow's winner will be he who best emulates Mr Clinton in capturing the centre ground. But there is something in the argument, eloquently expressed by the Labour MP, Denis MacShane, that to build on Mr Bush's campaigning success, if so it proves to be, Mr Hague would have to have two prominent blacks in his Shadow Cabinet, call for more immigrants to enter the UK, and speak in a foreign language to citizens whose first language isn't English, and move his party towards the centre. If Mr Bush wins it will no doubt encourage Mr Hague to make modest moves in that direction; but it is doubtful whether he has the time or freedom from his own hard right to ditch some of the more nationalistic strains in his own campaigning pitch.

This isn't to underestimate the challenges for Mr Blair in a Bush victory. He has the advantage of incumbency. And it has become commonplace that Mr Clinton would win if he were running tomorrow. Some hard choices, however, will become harder in a Blair second term if Mr Bush wins - like whether or not to infuriate some European partners, some of his own ministers and a good deal of British public opinion, by acceding to the request Mr Bush will undoubtedly make for help with National Missile Defence. And while Mr Clinton personally is likely to remain involved as an ex-president in international pursuit of Third Way ideas, Mr Blair may be obliged to accept that for the time being his politics are closer to a European than to a US model - something many pro-Europeans would welcome. For Mr Blair to meet those challenges may be difficult; but a lot easier than for the Eurosceptic William Hague.

Al Gore may yet win tomorrow. But if he doesn't, there is still an upside for Tony Blair if he is ready to exploit it.

d.macintyre@independent.co.uk