With the polls showing the election race between President Bush and John Kerry a statistical dead-heat, there are signs that the result could produce chaotic legal challenges and recounts, and not just in the several battleground states. Conor O'Clery, North America Editor, reports from New York.
Some 1.5 million Americans have already cast their votes in eight of the key swing states and millions more will vote in the seven days remaining before the official polling date of November 2nd. For the first time, 30 of the 50 US states are allowing residents to vote early in person, or to vote absentee without a reason, but this has led to complaints in key states where the presidential race hangs in the balance.
Election officials report a record early voting turnout because of the unprecedented interest in the election, and one in five electors will likely have cast their votes by election day.
In a hotly-contested case in Ohio, a federal appeals court ruled on Saturday that provisional ballots cast by voters outside their precincts should not be counted, rejecting a lower-court decision ruling such ballots valid if cast in the correct county.
Provisional ballots are counted after the election when they are inspected by election officials to establish their validity.
Democrats had complained about a ruling by Ohio's Republican Secretary of State, Kenneth Blackwell, that voters who came to the wrong precinct should not be allowed to vote.
The Ohio Democratic Party and a coalition of labour and voter rights groups had argued that Blackwell's order discriminated against the poor and minorities, who tend to move more frequently. Democrats earlier protested when Mr Blackwell attempted to reject tens of thousands of new registrations because they were not printed on heavy enough paper.
The issue of provisional ballots for eligible voters whose names do not appear on the rolls has also plagued several other states.
In Florida, a federal judge ruled last week that the state must reject provisional ballots if they are cast in the wrong precinct.
Yesterday, early voting picked up in the 'Sunshine State' after ministers in churches urged congregations to go to the polling stations after services. Nine legal actions have already been filed by Democrats in Florida where the latest Miami Herald poll shows the election deadlocked.
In one case, Democratic Congressman Robert Wexler took legal action to demand a paper backup for computerised voting machines. In Duval County, the location of bitter disputes in 2000, the county elections supervisor was replaced after local ministers alleged an effort to discourage turnout by blacks, who make up a quarter of the county's registered voters. Some 27,000 ballots, mostly from African-Americans, were rejected in 2000.
A spokesman for the Republican party in Florida criticised Democrats for challenging the interpretation of election laws, saying: "They're trying to create a scare, where people think, I don't know if my vote's going to count, they're trying to create the impression of chaos."
Republicans and Democrats are sending armies of volunteers and squads of lawyers across the country to monitor one of the most bitter and divisive elections in memory. In Florida, Ohio, Arizona and Wisconsin special efforts are being made by the Republican Party to place officials inside polling places to challenge the qualifications of voters they suspect are not eligible.
Challenges can be made on the grounds of age and residency, but some observers feel minority voters may be scared off by the prospect of questioning by official-looking monitors.
Republican Congressman Pat Tiberi in Ohio has alleged that in four counties more voters have registered than there are voting-age residents. Republicans in Wisconsin are checking on newly-registered voters through database searches, and in Nevada Democrats claimed that an employee of a company hired by the Republican Party to gather voter-registration forms tore up those signed by Democrats.
A poll in Time magazine finds that 48 per cent of voters believe that an "illegitimate" winner might emerge this year, given the closeness of the race and the fact that Mr Bush got the presidency without a majority of the popular vote. Yesterday former vice-president Al Gore, who in 2000 was denied a majority in Florida - and the election - when the Supreme Court stopped counting with George Bush ahead, campaigned in Jacksonville for Senator Kerry.