(San Francisco Chronicle) — If sales of presidential-candidate Halloween masks were votes, President Obama would have the November election in the bag.

As of this week, according to Spirit Halloween, one of the largest costume retailers in the country, the president is leading with 64 percent of its nationwide mask sales against Mitt Romney.

The New Jersey company, which has 1,000 stores in the United States and in Canada, has been predicting presidential elections since 1996 with searing accuracy based on its Presidential Index. The methodology is simple: He or she who sells the most masks wins.

“Well, then, I would like to see Harry Potter and Angry Birds on the ticket,” said Dan Newman, a Democratic strategist, who seemed dubious of Spirit Halloween’s unorthodox survey strategy. “They’ve got Obama doubling Romney. He’s not going to win 2-to-1. That’s just optimistic.”

But it isn’t crazy talk, said Lisa Barr, Spirit Halloween’s senior marketing director. The percentages on election day may not be the same as store sales, but, she said, “we pride ourselves on accurately predicting the race.”

Barr chuckled as she admitted that no, the Presidential Index isn’t scientific. Still, there’s no arguing with the company’s stellar record. In 1996, 71 percent of the presidential candidate masks sold were of Bill Clinton, compared with Bob Dole’s 29 percent. George W. Bush sold 57 percent against Al Gore in 2000 and then 65 percent against John Kerry in 2004. Obama sold 60 percent against John McCain in 2008.

Despite landslide sales of the president’s mask this year, Barr remained tentative about calling the race early. “Obama may be in the lead right now, but anything can happen,” she said. “We still have a month to go.”

This year, Spirit Halloween is also offering Hillary Clinton and Michelle Obama masks. The other hot sellers tend to be controversial figures, or people with a strong presence in the news. Last year there was a run on Anthony Weiner masks.

The U.S. representative from New York resigned in 2011 after getting caught in a sexting scandal.