Americans vote today in midterm elections that could change the balance of political power here, with Democrats seemingly set to recapture the House of Representatives for the first time in 12 years, and Republicans hoping to hang on to their control of the Senate, albeit with a sharply reduced majority.
As the campaign reached its climax, both parties poured money, workers and their star attractions - among them Bill Clinton for Democrats and First Lady Laura Bush for Republicans - to tilt the most closely fought contests.
Sometimes, local issues are uppermost in off-year elections. But these midterms, however, have been dominated by national issues, first and foremost the ever-more unpopular war in Iraq. In that sense, they have become a referendum on President George Bush, even though his name is not on the ballot.
At stake are all 435 House seats, 33 of the 100 Senate seats, and 36 of the 50 state governorships - and, if anything, the final polls have served to make the picture more confusing.
A clear-cut Democratic victory would be apparent by early in the evening, because many of the bellwether contests are on the East Coast, where the polls close earliest. But if the battle turns out to be close, the outcome may not be known until sometime tomorrow - or even later.
Yesterday, a new CNN poll put the Democrats ahead by a colossal 58 per cent to 38 per cent among likely voters - a margin that would translate into a landslide.
Other surveys show the race tightening, with the Democratic lead narrowing to seven points or less. The trend could reflect the Republicans' proven skill at mobilising their natural supporters in the closing stages of a campaign.
Averaged out, however, the polls are almost a mirror image of those before the 1994 midterms, when Republicans swept the board, in the process breaking their opponents' 40-year grip on the House of Representatives.
Despite a redistricting process that sharply reduced the number of competitive seats in the country, Democrats are quietly confident of making the net gain of 15 seats needed for a majority.
Some 40 House seats are reckoned to be vulnerable but only two of them are held by Democrats. Republicans tacitly concede at least 10 of them, meaning they have to score a virtual clean sweep of the rest to cling to a tiny majority. Democrats also expect to pick up some six governorships, including New York and Massachusetts.
The Senate, however, is a far tougher proposition. Seven Republican-held seats are in the Democracts' sights. But they have to win six of them, while keeping all the seats they are defending, if they are to overturn the current 55-45 Republican majority.
Despite the adverse national mood, Republicans still believe they have a shot at sneaking upset wins in either Maryland or New Jersey, seats which the Democrats currently hold.
Of the seven targeted pick-ups, three - in Pennsylvania, Ohio and Rhode Island - seemed likely last night. But the others, in the western state of Montana and the southern-central trio of Virginia, Tennessee and Missouri are toss-ups.
The most stunning upset perhaps would be in Virginia, where the incumbent Senator George Allen - who only a few months ago was seen as a sure winner and likely candidate for the 2008 Republican Presidential nomination - is in the fight of his political life against James Webb, a former Marine who served as Secretary of the Navy under Ronald Reagan before switching to the Democrats in protest over the Iraq war.
The battle between the two has been one of the nastiest in an election full of nasty contests, yet polls show them neck-and-neck.
In an extraordinary move, Mr Allen bought a two minutes of prime time on Virginia TV stations last night to make a personal election-eve appeal to voters, flanked by the state's hugely popular senior Senator, John Warner. The Republican candidate has suffered not only from racist and other gaffes, but also from the unpopularity of Mr Bush, whose approval ratings are once again below 40 per cent.
Over the past week the President has campaigned vigorously - but only in solidly Republican areas where no damage can be done.
Elsewhere, however, he is seen as a liability by Republican candidates. Charlie Crist, in a close battle to succeed the President's brother Jeb as governor of Florida, pointedly declined to appear with Mr Bush at a campaign rally in Pensacola, in the solidly Republican Florida panhandle, saying he preferred to seek votes in the south of the state, which is far less friendly territory for the President.
Events of the past few days have injected new uncertainty into the proceedings. Some analysts believe the death sentence handed down at the weekend against Saddam Hussein could make disillusioned Republican voters feel better about the Iraq war, whose shadow has dogged Republicans everywhere.
On the other side of the ledger, the disgrace of Ted Haggard, the former leader of the 30 million strong United States evangelical Christian community - who resigned after being caught up in a gay sex scandal - may hurt the Republicans.
Evangelicals are among the party's largest and most active constituencies. It will only become clear today as the votes are counted whether the downfall of Mr Haggard has deterred some of his followers from going to the polls.
Meanwhile, Mr Bush and other top Republican leaders have been trumpeting the successes of the economy, as highlighted by last week's drop in the jobless rate to a five-year low. They have also accused Democrats of spinelessness on Iraq, and weakness in the war on terrorism.
But this time they are finding it much harder to play the national security card than in 2002 and 2004. Polls say voters are readier to trust Democrats, not only on the war, but as the party more likely to keep the country safe.
The battles in the headlines
First female Speaker?
Nancy Pelosi is an all-but certain winner in California's 8th Congressional District, in San Francisco, but the 66-year-old Democrat is poised for even greater things if her party seizes control of the House, where she is party leader. Mrs Pelosi would become the first woman Speaker in US history - directing legislative initiatives and, under the constitution, becoming third in line to the presidency.
Stem cell ban?
In one of more than 200 ballot referenda taking place across the country, voters in Missouri have to decide whether to allow stem-cell research, something the Christian right has long opposed. The debate is split largely on party lines, with the actor Michael J Fox, below, who has Parkinson's disease, campaigning for the measure. In the Senate race, the Republican Jim Talent has opposed the measure and Democrat Claire McCaskill backs research.
Earlier this year there was drama when the incumbent Democrat Senator of Connecticut, Joe Lieberman, who was his party's vice-presidential candidate in 2000, lost the primary election to an anti-war challenger. Ned Lamont had criticised Mr Lieberman's support for George Bush over Iraq. Mr Lieberman is now running as an independent and it looks very likely that he will win the seat.
South to get first black Senator?
Democratic Congressman Harold Ford Jnr is battling for the Senate seat in Tennessee. If he wins, he will be the first black Senator from the South since Reconstruction, but the Republican Bob Corker appears to be leading. A Republican TV ad implied Mr Ford had partied with a Playboy girl.
Montana is usually considered safe Republican territory but the incumbent Republican, Senator Conrad Burns, is in one of the tightest races in the country, having seen his support plummet because of his links to a disgraced lobbyist. This is one of the seats the Democrats must win if they are to take the Senate.
A former Virginia governor, Republican George Allen seemed set for easy re-election as Senator and was talked of as a possible presidential candidate. But a series of controversies, many relating to racial issues, have left him tied with Democrat Jim Webb, a military veteran and former secretary of the navy. This is another must-win for the Democrats.
Democrat Elliot Spitzer, currently New York's Attorney General, is battling to become the state's governor - a race which pits him against Republican John Faso. Polls give Mr Spitzer, above, a huge 72-22 lead, setting the scene for a historic landslide.
In perhaps the most controversial "ballot initiative", voters in South Dakota must decide whether to keep or reject legislation that bans abortion under every circumstance, with the sole exception of an imminent threat to the life of the pregnant woman. Activists on both sides of the national abortion debate see this as a historic test.
Independent Congressman Bernie Sanders appears set to become America's first socialist Senator. Polls in Vermont show Mr Sanders to be far ahead of his Republican rival Rich Tarrant, a wealthy businessman who has stepped into politics for the first time.Reuse content