Democrat Barack Obama and Republican John McCain are seeking support in the key industrial states of Ohio and Pennsylvania in the final 48 hours of the White House race.
The Illinois senator plans rallies in the three biggest cities in the showdown state of Ohio, and launched a new advertisement emphasising ties between Mr McCain and unpopular Vice President Dick Cheney.
‘I'm delighted to support John McCain," Mr Cheney says in the ad, shot at a campaign event yesterday in Wyoming. He also praises McCain's running mate, Alaska Governor Sarah Palin. ‘That's not the change we need,’ the ad's announcer said.
Senator McCain trails Senator Obama in every national opinion poll and in many crucial battleground states ahead of Tuesday's vote, but aides say he is closing the gap at the end of a campaign that has lasted nearly two years and cost more than $2 billion.
‘What we're in for is a slam-bang finish,’ McCain campaign manager Rick Davis said on ‘Fox News Sunday’.
‘He's been counted out before and won these kinds of states, and we're in the process of winning them right now,’ Mr Davis said of big battleground states like Ohio, Florida and Virginia.
Those states are the focus of the race's final days as each candidate searches for the 270 electoral votes needed to win.
John McCain is struggling to defend about a dozen states won by President George W Bush in 2004, and polls show Barack Obama ahead or running even in key states like Ohio, Florida, Virginia, Colorado, Indiana, North Carolina and Nevada.
A new poll in Ohio showed Mr McCain with a two point advantage, although other surveys gave Barack Obama a narrow edge.
John McCain's prime hope of a breakthrough in a Democratic-leaning state is Pennsylvania, won by Democrats in the last four presidential elections.
MR Obama has led in every opinion poll in the state this month, although his edge has narrowed from double digits to between 4 and 7 points.
