AS CAMPAIGNING gets under way in earnest for the midterm elections in November, Democrats believe that they have a gilt-edged opportunity to end years of Republican hegemony in Congress.

They must make a net gain of 15 seats to recapture the 435-seat House of Representatives, where the Republicans have been in the majority since 1994. Winning back the Senate, controlled by Republicans for the past four years, by gaining six additional seats out of the thirty-three being contested this year will be harder for the Democrats. But the combination of George Bush’s unpopularity, deep unease over the war in Iraq and voter anger over high petrol prices have made the prospect of victory seem at least possible.

The President’s approval ratings are about ten points lower than those enjoyed by Bill Clinton in 1994 when the Democrats lost fifty-three seats in the House and eight in the Senate. Polls also show that three quarters of voters are angry or unhappy about the direction of their country, the same proportion as 12 years ago, when the Republican hold on Congress began.

There are still good reasons to believe that the party will not suffer the same scale of defeat that it inflicted on the Democrats then, not least because of its superior capacity to get its vote out and the deep pockets that should ensure that it can outspend Democrats by at least $100 million (£53 million) this year.

But should the Republicans lose control of one or both Houses of Congress, no one doubts that there will be profound consequences for the direction of policy in Iraq and elsewhere. Mr Bush has adopted a high-risk strategy over the past week of seeking to “nationalise” the debate by embarking on a speaking tour where almost every day he has concentrated on the War on Terror.

Some Republican strategists believe their best chance of avoiding defeat is to fight local battles and rely on the power of incumbency, but the President is determinedly focusing attention on national security — as he did so successfully in the 2002 midterm elections and the 2004 presidential contest.

Yesterday in Atlanta, Georgia, he promised that the US would not let up on al-Qaeda, at least under his watch. All this is leading up to the anniversary of 9/11 with the clear implication that the Democrats would leave America more vulnerable to further attacks.

The Democrats deny that they would cut congressional funding for the War on Terror — at least in the short term — but have promised to start bringing troops home from Iraq, arguing that the war has been a distraction from the real battle against al-Qaeda. A Democrat victory in November would hobble this Administration’s final two years as congressional inquiries unpick some of the darker episodes of Mr Bush’s War on Terror.

John Podesta, Mr Clinton’s former chief of staff who now runs the think-tank Centre for American Progress, said yesterday: “If the Republicans continue to control both Houses of Congress there will be no accountability and no change of direction. If the Democrats take over, there will be the capacity to force Bush to answer some hard questions which, left to his own devices, he would ignore.”

Over the summer the number of Republican House seats on the “watch list” for vulnerability has doubled to about 40. Significantly, these include swaths of the suburban north and Midwest — across Pennsylvania, Ohio, Connecticut, New York, Indiana, New Hampshire, Illinois, Iowa, Minnesota and Wisconsin — which for most of the past century were Republican strongholds. But just as the southern states have moved remorselessly out of Democrat hands, the states carried by Abraham Lincoln in 1860 are moving in the other direction, propelled by what pollsters believe is a growing mood of economic and personal insecurity.

At the same time America appears to have lost its habit of “split-ticket votes” between congressional and presidential elections. This means that the results on November 7 will be a good guide to what may happen in 2008, when Mr Bush’s successor is elected.

If the Republicans do badly it may serve to crystallise support for John McCain, the Arizona senator who has broad appeal among independents and even Democrats. He is probably the front-runner for the Republican nomination even though he remains distrusted by many party activists.

A substantial Democrat victory could help to dispel lingering doubts about Senator Hillary Clinton’s capacity to win a national election — rather than merely the Democratic nomination in 2008. But it might also encourage radical Democrats to support a candidate such as Senator Russ Feingold, who has always opposed the war, or John Edwards, who has renounced support for it.

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