U.S. President Barack Obama (R) and Republican presidential candidate Mitt Romney (L) attend the final presidential debate on foreign policy at Lynn University in Boca Raton, Florida, on Oct. 22, 2012. (Xinhua/Pool/Win McNamee)

After months of campaigning and millions of dollars in advertising, the 2012 U.S. Presidential Election is now less than 72 hours away, with the outcome still far from certain.

Though political analysts have long held that 2012 election would be a close one, some may still be surprised that President Barack Obama who according to Gallup polling posted a seven percentage point lead as late as September is now tied with Republican challenger Mitt Romney.

According to the latest Gallup poll released Oct. 28, the U.S. presidential race remains dead even, with each candidate posting 48 percent support. A Nov. 3 Rasmussen survey showed the same result as Gallup, with a margin of error of 2.5 percentage points.

While some may point to Obama' s oft-criticized performance in the first presidential debate as responsible for the shakeup in momentum, University of Chicago Professor John Mark Hansen argues that the tightening in polls was bound to happen as the campaign draws to a close.

"I don' t think there was ever any prospect that Barack Obama would win this election by five to eight percentage points," Hansen told Xinhua in an interview, adding that "the conditions dictate that it is a very, very close election."

According to Hansen, the 2012 race closely resembles the conditions of the 2004 election, where President George W. Bush enjoyed all the power and advantages of incumbency, but did not appear as a prohibitive favorite.

Similarly, while Obama remains more popular than Bush was towards the end of his presidency, Obama also has the disadvantage of presiding over a still-weak economy, and Hansen said historically presidents that run in poor economic conditions tend to do worse.

Romney, meanwhile, faces the challenge of overcoming Obama leads in crucial swing states like Ohio and Florida. According to the latest NBC News/Wall Street Journal/Marist polls released Nov. 3, Romney currently trails Obama by six points in Ohio, and two points in Florida.

The Ohio data is of particular concern to the Romney camp, as no Republican has ever won the White House without taking Ohio. Without Ohio, Romney' s path becomes very difficult, as he would have pick up other swing states like Wisconsin and Pennsylvania, which are much less in play.

The critical importance of swing states speaks to the peculiar nature of the U.S. election, which is decided not by a popular majority of votes nationwide, but rather by a majority of state votes in the electoral college.

Because of the characteristics of the electoral college and the importance it places upon winning states rather than people, Hansen and other experts have predicted that Obama will ultimately secure victory thanks to strong battleground performances, though it will be by a slim margin.

However, given Romney' s even polling in recent surveys, it is possible that Romney could lose the electoral contest but win the popular vote nationwide - a fate similar to that of Democratic candidate Al Gore in the 2000 election.

While Hansen said he thought it unlikely the 2012 race would see a repeat of the 2000 election where the victor lost the popular vote, he did not discount the possibility.

"Electoral college anomalies like that aren' t very common, but they are much more likely in a season where the popular vote is as close as it' s likely to be," Hansen told Xinhua.

With the numbers still questionable, both Obama and Romney are spending the last weekend before the election scrambling to make their final pitches to swing state voters, some of whom still remain undecided.

Both Obama and Romney are scheduled to travel cross-country holding events in Ohio, Wisconsin, New Hampshire, Colorado, Iowa and Virginia, with Romney additionally stumping in Pennsylvania.

In 2008, Obama won the presidential election with 365 electoral votes and 52.9 percent of the popular vote.