'October surprise?'

Washington - A halt to bombing of North Vietnam, a conspiracy theory about US hostages in Iran, and a video of Osama bin Laden. All had one thing in common - they were unforeseen "October surprises" which may have swayed US elections.

Just days before the November 4 election after a gargantuan presidential race, the teams of Republican John McCain and Democrat Barack Obama must be holding their breath over the possibility of dramatic last-minute revelations that could hurt - or salvage - their campaigns.

As Obama surges towards the finish line with polls across the country showing him ahead of his rival, pundits and bloggers have suggested it would take nothing less than a dramatic October game-changer to derail Obama's White House express.

Some have said the month's seismic event would be a return to the media maelstrom of Obama's inflammatory former pastor Jeremiah Wright, who has remained off the radar in recent months.

Others believed Obama's running mate Joe Biden provided the seed earlier this week when he highlighted the Illinois senator's lack of foreign policy experience by saying "it will not be six months before the world tests Barack Obama".

The fearful spectre of terrorism, in a country still deeply scared by the September 11, 2001 attacks, could be just such a test, and some analysts predict it may make a last-minute intrusion onto the campaign that could force millions of voters to re-evaluate their allegiances.

"Something else is going to happen," columnist Jonathan Alter wrote in Newsweek.

'My money is on Osama bin Laden...'

"My money is on Osama bin Laden popping back up with a hate video, just as he did the weekend before the 2004 election," in the October surprise which may have had the most impact on any modern-day election.

On October 29, 2004, Al-Jazeera aired a video of the world's most wanted man, who reportedly called on Americans to "return to what is right" rather than support "the liar in the White House" to avoid a repeat of the 2001 attacks.

President George W Bush was seen as receiving a "bounce" from the video, which may have tipped the election considering Bush won Ohio by less than 120 000 votes. A victory by Democratic challenger John Kerry in Ohio would have given him the White House.

Los Angeles police chief William Bratton and RP Eddy, a former director of counterterrorism at the National Security Council, argued last week that it would be "tempting" for bin Laden to lash out this month.

"If bin Laden wants to engineer a late-October surprise in 2008, an attack on a significant American economic target may be one of the most tempting opportunities he has had in recent years," they wrote in the New York Daily News.

"Given our current financial turmoil, bin Laden may believe that a strike against the US could push our economy over the edge."

Several other presidential campaigns over the past 40 years have seen October surprises.

Most famous October surprise

The term was likely first used to describe Democratic president Lyndon Johnson's announcement on October 31, 1968 - five days before the election - that he was halting the bombing of North Vietnam, citing progress in Paris peace talks.

Republican Richard Nixon was narrowly ahead in polls, and while Johnson announced in March that he would not seek another term, he wanted to convince voters that negotiations with Hanoi were bearing fruit.

It didn't work, and Democrat Hubert Humphrey lost by half a million votes.

Four years later, it was Nixon's turn to drop his own October bombshell with his secretary of state Henry Kissinger announcing there was "peace at hand" in Vietnam, even as Nixon had failed to end the war in his first term.

Nixon defeated Democrat George McGovern in one of the largest landslides in American history.

The most famous October surprise came in 1980 when the run-up to the election was gripped by a conspiracy theory over the US hostages held in Iran.

A Washington Post report at the time alleged that Jimmy Carter's administration was preparing a military operation to rescue the hostages in order to help him get elected.

Accusations quickly emerged that Republican challenger Ronald Reagan's team was secretly working to thwart the release - contentions that were debated for years, even as congressional probes concluded there was no plan to delay the hostage release.

Shortly before the election, Carter announced Tehran had decided not to release the hostages until after the vote. They ended up doing so just minutes after Reagan, who defeated Carter in a landslide, was inaugurated in January 1980.

- AFP