The best news as 2008 dawns, of course, is that this most endless of presidential campaigns now finally reaches a point at which something actually happens. Finally the people will speak, starting on Jan. 3 in Iowa. So what will they say? The races in both parties have developed along very unexpected lines, making this probably the most fascinating presidential election in decades.

Let’s start with the Republicans. Here we have the most unpopular sitting president since Richard Nixon. Significant majorities of his countrymen have long since concluded that they made a mistake in electing him; that he isn’t up to the job; that he basically lied us into a war; that his domestic policies have been at best no great shakes; and that the conservative ideology to which he has been in thrall has not served the country well, to put it mildly.

And yet, by and large, the Republican candidates are running on exactly the same policies that Bush has pursued. Consider this list. All the major Republican candidates want to “stay the course” in Iraq, denouncing any discussion of withdrawal as evidence of pusillanimity. All see the fight against terrorism in more or less Bushian terms. All want to make the Bush tax cuts, now scheduled to sunset in 2010, permanent — even John McCain, who at the time voted against them. All have promised the leaders of the Christian right that they will appoint supreme court judges “in the mould of” Antonin Scalia and Clarence Thomas.

What this euphemistic language means is that whatever a candidate’s previous positions on abortion and gay rights — Rudy Giuliani, for instance, has supported both — the leaders of the religious conservative movement have exacted commitments from all the Grand Old Party candidates to appoint the kind of judges they want, and that matters far more than past positions.

There’s more. Healthcare is a priority in this election. But to hear these Republicans, you’d never know it. Their healthcare plans range from cynical to inadequate. Climate change? They barely acknowledge the problem and are particularly loath to acknowledge that human activity has contributed to it. They continue to insist, as Republicans since Ronald Reagan have, that the only real domestic enemy the American people face is the federal government, which they continue to want to starve. The real question then is how the next Republican will govern should he happen to win. And the answer to that question is that there’s every reason to assume that he will be just as a conservative as Bush.

On the Democratic side, there is far more divergence. Not so much on policy — they’re all for universal or nearly universal healthcare, for getting out of Iraq, for doing more for unions, for bringing some equity and progressivity to our taxation system and so on. If you’d asked me a year ago what the major Democrats’ positions on the leading issues would be, I would not have guessed that they’d be this uniformly liberal.

Whichever theory of change Democratic voters nominate, and whichever theory of statis Republican voters select, the choice before Americans in November will be stark. In 2004, many Americans, particularly liberals fearful about a second Bush term, took to calling that election “the most important of my lifetime”. And it was, for a while. Now this one is. — The Guardian