NEW YORK (CNNMoney) -- Polls may show a hotly contested presidential election. But sales of Halloween masks of the candidates are already calling the race.

President Obama masks have been outselling those of his Republican challenger Mitt Romney by a 60% to 40% margin, according to Spirit Halloween, the country's largest seasonal Halloween retailer.

The 1,000-store chain even has its own "presidential index," which uses nationwide sales of candidates' masks to predict the outcome of the most important U.S. election every four years.

As unscientific as the methodology may be, Spirit Halloween has accurately predicted the election winner by charting national mask sales since it started keeping track in 1996.

Obama beat out Sen. John McCain in mask sales in 2008 with the same split as this year. The retailer also predicted a President George W. Bush win over Sen. John Kerry in 2004, a 2000 Bush victory over former Vice President Al Gore, and a Sen. Bob Dole defeat by President Bill Clinton in 1996.   Read more at CNN Money