Jacksonville, Nov. 3 - Barack Obama stood on the threshold of history Monday as polls gave the Democrat a solid lead over John McCain on the last day of campaigning for the most dramatic US presidential vote in a generation.

But McCain, who has no room for error in the tense battle for a handful of toss-up states, vowed to confound the pollsters and wrench victory from the African-American’s grasp on Tuesday.

History

The 47-year-old Democrat stressed the historic nature of his quest to be America’s first black president, striking an optimistic tone as fresh polls gave him a wide lead and heaped further pressure on McCain.

"This is a defining moment in our history," Obama wrote in an article published in The Wall Street Journal.

"Tomorrow, I ask you to write our nation’s next great chapter... If you give me your vote, we won’t just win this election -- together, we will change this country and change the world."

McCain, a 72-year-old former prisoner of war in Vietnam, was defiant. "My opponent is measuring the drapes at the White House," he said, as he wrapped up a frenzied day of campaigning with a midnight rally in Miami.

"The Mac is back! And we’re going to win this election," he added.

The Republican was to dash through at least seven states on the marathon campaign’s final day. Obama was to blitz through Florida, North Carolina and Virginia bidding to storm Republican bastions and turn them over to his side.

Rallying supporters in Ohio on Sunday, Obama said his rival’s policies would extend President George W. Bush’s legacy of financial crisis and "war without end" in Iraq.

In his own Wall Street Journal article, McCain shot back at his rival on the economy. "Senator Obama wants to raise taxes and restrict trade," he charged. "The last time America did that in a bad economy it led to the Great Depression."

The final pre-election poll of Gallup-USA Today published Monday gave Obama a yawning lead of 11 points -- 55 per cent to 44 for McCain.

"It would take an improbable last-minute shift in voter preferences, or a huge Republican advantage in election day turnout, for McCain to improve enough upon his predicted share of the vote... to overcome his deficit to Obama," the pollster said.

A new Wall Street Journal-NBC News poll put Obama ahead on 51 per cent to 43. CNN’s latest poll on Sunday had Obama with a 53-46 per cent edge, a Washington Post-ABC News poll gave him 54 per cent to 43, and Rasmussen said he was at 51 per cent to McCain’s 46.

Obama also leads by slimmer margins in the battleground states where the election will be won and lost, including in states such as Virginia and North Carolina that have not backed a Democratic hopeful in decades.

Poll reports

A Quinnipiac University poll examining the three states with the largest number of electoral votes -- Ohio, Pennsylvania and Florida -- found Obama’s lead had narrowed slightly to 51-42 in Ohio and 53-41 in Pennsylvania, while Florida was too close to call.

A separate poll by The Washington Post and ABC said that in six states considered to be up for grabs, support was roughly split with 51 per cent support for Obama and 47 for McCain.

And a CNN/Opinion Research Corporation (ORC) survey released Monday said that 59 per cent of voters feel Obama can bring "change," while about the same number say McCain cannot, the network reported on its website.

McCain’s whistlestop tour Monday was expected to include campaign stops in Florida, Virginia, Pennsylvania, Tennessee, Indiana, New Mexico and Nevada before he was to head home to Arizona.

Another CNN/ORC poll meanwhile suggested that McCain’s running mate, Sarah Palin, may be dragging down the Republican’s chances. The news network said McCain had 48 per cent support, but backing for McCain and Palin as a unit was lower, at 46 per cent.

The battle has narrowed to states that have been reliably Republican in recent elections, as Obama’s deep-pocketed campaign expands to places where the Democrats have not won in years.

Victories in Colorado and Nevada out west, on top of his lock on Iowa in the US heartland, would let Obama clinch the White House without even winning the states that decided the past two elections: Ohio and Florida.

To win, a candidate needs to gain 270 votes in the Electoral College that formally selects the next president. States are apportioned electoral votes according to the size of their population and in most cases the winner of a state’s popular vote gets all its electoral ones.

McCain’s blitz

In Tampa, Florida, Republican John McCain launched an election-eve sprint across seven states Monday, defiantly predicting victory despite polls showing him lagging behind Democratic rival Barack Obama.

In the shadow of the 65,000-seat Raymond James Stadium -- the sort of venue Obama has been packing regularly during his campaign -- McCain told a small crowd of around 500 supporters to prepare for victory.

"There’s one day left until we take America in a new direction," McCain told the crowd. "The pundits may not know it and the Democrats may not know it but the ‘Mac is back’ and we’re going to win this election."

McCain wrapped up his speech with his now familiar rallying cry, urging his supporters to "fight" to the very end.

"I’m an American and I choose to fight. Don’t give up hope, be strong, have courage and fight," he exhorted.

"Stand up, stand up, stand up and fight. America is worth fighting for, nothing is inevitable here ... Now let’s go win this election."

McCain had planned to ease off the pedal on election day, when candidates usually have nothing to do but cast their vote and watch the returns come in.

However, campaign manager Rick Davis told reporters late Sunday that McCain was now planning an 11th-hour get-out-the-vote campaign in the neighboring western states of New Mexico and Colorado.