US election much too close to call

Ignore the choreographed bonhomie and canned gravitas on stage as President Barack Obama and his Republican rival Mitt Romney launch their final rallies - the 2012 race for the White House is coming down to a desperate, gritty fight to the finish.

While Romney and Obama have shouted themselves hoarse as they dash across the swing states such as Ohio, New Hampshire, Florida, Wisconsin and Virginia before polls open today, their campaign workers speak of near-exhaustion - and fears the race is simply too close to call.

Voters in key counties within the 11 or so crucial states also talk of exhaustion - at the blitzkrieg of late advertising, door knocks and meal-time phone calls.

It is not just that national popularity polls suggest a near dead-lock, it is lingering doubts about each candidate. Republicans ponder the thwarting of Romney's late surge while Democrats acknowledge question marks over the true strength and depth of Obama's support after four tough years. Today will tell.

Officially at least, Obama's core advisers such as David Axelrod, the architect of his stunning political rise from the Illinois state senate, are expressing confidence in polls showing an edge in the crucial Electoral College.

On the ground it is a slightly different story. For all the star-power of Obama's recent rallies - singers Stevie Wonder, Katy Perry and Bruce Springsteen have all been pressed into service - the crowds are smaller and passion notably weaker compared to the dramatic scenes of 2008. Then Obama could move supporters to tears as he closed in on the prospect of an historic victory.