Liberals in America no longer make predictions. Indeed it is all they can do to hope. Instead they watch these midterms like children watching a horror movie - peeking through open fingers with their hands half-covering their eyes.

They have a sense of what is to come but until it is over they are waiting to exhale. Six years into a Bush administration humility comes more naturally than hubris. It's as though saying they might win on Tuesday is one of the most certain ways of making sure that they don't.

Given the cruel conclusion to election day two years ago, when exit polls predicted a victory for John Kerry only for the actual polls to deliver the White House to Bush, their caution is understandable.

But then you pick up a copy of the Denver Post and wonder if the die could really roll more in their favour.

The front page splash is not, strictly speaking, an election story but the tale of how a prominent local pastor and the president of the National Association of Evangelicals, Ted Haggard, is allegedly involved in a scandal involving gay sex with a prostitute after taking methamphetamine. Haggard was an outspoken critic of gay marriage, and has denied the accusations.

The other story suggests a 3.5% rise in registered Latino voters galvanised by immigration issues. In an area with several tight races and a ballot on equal rights for domestic partners, such news does not suggest Democrats are out of luck.

Indeed, much of the liberal anxiety appears rooted in the notion that Republicans have superhuman powers. True, the right has both money and organisation on their side. Their get out the vote (GOTV) drive for the final 72 hours of the campaign is referred to with the kind of awe usually reserved for military campaigns and illusionists. But the truth is with bad candidates and worse policies you can only do so much.

Lest we forget, the Republicans did not win the election in 2000 and barely squeaked by four years later after 9/11 and in the midst of a war. Their strategy has revolved around winning a landslide but just over 50% of the vote. They achieved this by relying on a sizeable majority of white men, evangelical Protestants and the rich, and very narrow majorities of white women and Catholics. To send them over the edge they chipped away at Democratic majorities among Latinos, African Americans and Jews - still losing considerably but with enough extra votes to break the 50% barrier.

Well, since 2004 there has been hurricane Katrina, the failed attempt to nominate Harriet Miers, the bungled effort to privatise social security, no push for a federal ban on gay marriage and a rapidly deteriorating situation in Iraq. Bush claimed he had a mandate. Apart from two supreme court nominations he has precious little to show for it.

Support among all elements of the Republican base has fallen considerably with polls showing Republicans losing among white Catholics, rural voters and young and old men.

Meanwhile those minority constituencies he courted have been even more alienated. Latinos are energised by the immigration debate. And African Americans are still so angry at Katrina that some polls have put their approval ratings of the president so low that they are within the margin of error of actually being negative. There may be black babies not even born yet who disapprove of Bush from the womb or dead African Americans who loathe him from the grave.

On the street there is a real shift in emphasis since 2004. Back then the issue was "do you hate Bush or do you love him"?. Now, among those people who are focused on the campaign - midterm turnout is often pathetically low - the question is "are your prepared to defend him or have you had enough"?.

If proof were needed that the Republicans are running scared, just look at Bush's itinerary. Yesterday he was in Montana, a state he won by 59% two years ago where the Democrats now threaten to take a Senate seat; on Sunday he is in Nebraska where Democrats have mounted a challenge in a seat the Republicans won with 87% of the vote two years ago. Follow the Republican money and it is coming out of seats they once thought were close and heading for those they now fear they could lose. Follow the Democratic money and it is shifting to races they felt they had little chance of winning just a couple of weeks ago.

Where the Senate is concerned, how all of this will pan out on election day is a tough call, but in all likelihood the Democrats will come close but not close enough.

As for the House, the issue still seems to be not whether the Democrats take it but by how much. A huge number of races will be decided by the narrowest of votes. There are still a large number of undecideds and endless opportunities for more Kerry-like gaffes. The one thing there is an exhaustible quantity of is time.

The Democrat majority could be thin - but it could be huge. Since I'm neither American nor a liberal I would predict thin and hope for huge. Either way, when American progressives dare to peek through their fingers on Wednesday morning I think they will like what they see.