Republicans prepare for the worst as disaster looms in midterm elections

After one of the hardest-fought election campaigns of recent years, America will vote in the midterms tomorrow, with the latest polls suggesting that Democrats will seize control of the House of Representatives and possibly take the Senate as well. Such a result would be devastating not just to the Republicans but also to President George Bush, whose widespread unpopularity over the war in Iraq has put his party on the defensive across the nation.

In public, senior Republicans still argue that they will retain control of both houses of Congress. But in private, the party appears to be preparing for defeat - almost certainly in the House, where Nancy Pelosi would become the first female speaker, and possibly in the second chamber, though polls show that battle tightening.

"It's the worst political environment for Republican candidates since Watergate," Glen Bolger, a Republican pollster who has worked on many of the election's closest races, told The New York Times.

Strategists for both parties believe that the outcome will depend heavily on how effective each will be at getting out their voters. Events such as the Mark Foley scandal might be thought likely to dissuade some conservatives from voting.

More recently, the Republicans have been hit by the resignation of Ted Haggard as president of the National Association of Evangelicals after he hired a gay prostitute. The Rev Haggard, who has lobbied in Washington against homosexuality, wrote to his former congregation in Colorado yesterday admitting that he was guilty of sexual immorality. "I am a deceiver and a liar," he wrote. "There's a part of my life that is so repulsive and dark that I have been warring against it all of my adult life."

Still, the Republicans are acknowledged to have the most effective grass-roots operation, and Mr Bush's senior political adviser, Karl Rove, has always stressed the need to get out the "base". In important election battles, such as the Senate races in Missouri, Montana and Virginia, the size of the turn-out is likely to be the crucial factor. Whether Saddam Hussein's guilty verdict in Baghdad makes any last-minute impact is unclear.

To win the House, Democrats need to gain at least 15 seats. The political analyst Charlie Cook said that in the battle for the House, the only question remaining was the size of the Democratic victory. "It's hard to imagine how the House majority does not turn over. It's a question of how big this thing will be," he told the Political Wire website. "After a certain point, you aren't really counting or even estimating, you're pulling numbers out of the air. I don't see any point in that. Let's just say it's 20-35 [seats gained for the Democrats], but that the possibility of this getting bigger, is real."

In the Senate, where the Democrats need to win six seats, the outcome is much less predictable. While the party appears confident of winning three seats, the polls in several other states have tightened in recent days - most notably in Montana, where a visit by Mr Bush appears to have boosted the numbers of incumbent Republican Conrad Burns, who had previously been behind. He is now tied with his rival.

Likewise in Rhode Island, Lincoln Chaffee, a moderate Republican, appears to have made a last-minute recovery. A poll for the McClatchy newspaper group and MSNBC gives him a 46-45 advantage - a statistical tie given the margin of error - over the Democrat Sheldon Whitehouse.

Despite this, senior Democrats were talking up their chances of securing both chambers of Congress. Charles Schumer, the chairman of the Democratic Senatorial Campaign, said on NBC's Meet the Press: "In [Democratic] states in particular, the wind is at our back.... I wouldn't get the champagne out yet but we are feeling very good, something we would not have said just three months ago."

One sign of the Republicans' concern has been the decision to use Mr Bush to campaign in party strongholds. Because of his low approval rating, Mr Bush has been unwelcome in some battlegrounds and so strategists have used him to rally the party faithful in traditional Republican states. This weekend, he was campaigning in Colorado and Nebraska, two states normally considered safe Republican territory and not requiring the President's presence to ensure victory.

A great deal is at stake in these elections. If the Democrats seize control of either chamber they would be able not only to introduce their own legislative plans but also to launch congressional investigations into everything from the war in Iraq to the federal response to Hurricane Katrina. They would do everything they could to harry Mr Bush during the last two years of his presidency.