With barely more than two weeks left until Election Day, the numbers suggest that President Obama maintains a tightening lead over Mitt Romney.  But what could radically alter the outcome over the final 15 days?

One factor that could influence voter attitudes is the October jobs report.  Signs of an even weaker economy — including higher unemployment and anemic job growth — could work against the president.  The sudden September unemployment drop from 8.1 to 7.8 percent, an unexpected development, was the lowest jobless rate since March 2009, only a few months after Obama was inaugurated.  This was a positive development for Obama, given that no U.S. president has been reelected with unemployment above 8 percent.

The jobs report for October will be released Nov. 2 , only four days before voters head to the polls.

Jobs and the economy are the issues foremost in voters’ minds.  If unemployment increases in the coming weeks, Romney could use it to his advantage by painting the president as a purveyor of failed economic policies, and by continuing to portray himself as a “job creator” who worked in the private sector and knows how to grow the economy.  Meanwhile, the president and his allies would point out that Romney provides no evidence to support his promise of the 12 million jobs he would create if elected.

A pre-election terrorist attack is another event to potentially impact the election.  Mitt Romney would use such an incident to highlight the president’s handling of foreign policy, particularly on the heels of the deadly siege on the U.S. consulate in Benghazi, Libya.  However, a terrorist attack could also help to boost Obama, in the manner that Bush was the beneficiary of good will following the 9-11 attacks, despite perceived intelligence missteps by the Bush administration.  There would be danger in Romney criticizing his opponent in the wake of a terrorist attack, given widespread public criticism of Romney’s Libya remarks, and the lack of foreign policy experience on the Romney-Ryan ticket.  Meanwhile, Secretary of State Hillary Clinton has enjoyed near record-high favorability, and President Obama is known as the man who killed Osama bin Laden.

Viewed as crucial, the next and final presidential debate will allow the candidates to sway undecided voters on foreign policy.  But the debate will also provide opportunities for a “gotcha” moment — a gaffe, misstatement or poor performance by one of the two candidates, which the other will undoubtedly use as political fodder for a campaign ad.  The president’s lackluster performance in the Denver debate allowed an opening for Romney in the polls, while Gov. Romney’s “binders full of women” comment in Hempstead, New York reinforced perceptions that the Republicans are insensitive to women’s issues.

Finally, an “October surprise” in the final days of October has the potential to alter the course of events and the outcome of the election.  The original October surprise was the breakdown in talks between President Jimmy Carter and Iran over the release of American hostages, just two days before the 1980 election.

Other potential game changers include an eleventh-hour White House deal with Iran over nuclear inspections on the eve of the election, or conversely, an American and Israeli airstrike on Iran.

Follow David A. Love on Twitter at @davidalove