In the two weeks since a billboard showcasing presidential candidate Newt Gingrich went up on Route 1 in Bucks County, the one-time Republican front-runner has collapsed at the polls.

Could the backing of a "cheaters" website that encourages extramarital affairs be the reason why?

Well, no. Gingrich didn't need any help with that.

But even as he and other candidates vie for GOP voters' affections in Iowa, the billboard - which reads "Faithful Republican, Unfaithful Husband. Welcome to the AshleyMadison.com Era" - has brought unwanted attention to the Bucks County town of Morrisville.

Ashley Madison is an online dating site for married people who want to fool around. Gingrich knows something about that, having admitted that he cheated on his first two wives.

Noel Biderman, founder and chief executive officer of Ashley Madison, which paid for the sign that overlooks Route 1 just before it crosses the Delaware River into New Jersey, doesn't think making Gingrich a poster boy for adultery caused the candidate's recent slip in popularity (though straight arrow Rick Santorum has surged in the latest Iowa polls).

"That would be awful if that was the case," said Biderman, a sports lawyer turned Internet entrepreneur. "His reputation as a philanderer is why we're behind him."

The Gingrich campaign had no comment.

Biderman said he used the former House speaker in the ad because he wanted to show that marital fidelity has no bearing on someone's ability to do a job.

"He struggles, like many others do, around the notion of sexual monogamy, but that doesn't mean he isn't super-qualified to lead the country," said Biderman, who founded his company in 2001 after reading that from 25 percent to 30 percent of people on singles dating sites aren't single at all. He boasts that Ashley Madison is now the third-largest Internet dating site in North America.

Gingrich isn't the first politician to get the dubious honor of Ashley Madison's seal of approval. The cheesy advertising campaign started when then-New York Gov. Eliot Spitzer was caught in a rendezvous with a costly call girl. The company ran a full-page newspaper ad saying Spitzer would have avoided getting caught if he had used Ashley Madison instead.

For Biderman, supporting hound-dog politicians is as American as, well, hound-dog politicians.

"If we keep trying to whittle down the pool of leadership, America is going to become a very dull country, more representative of places like China and Iran, rather than the symbol of democracy we're known for," he said in an interview.

Bad boys from former California Gov. Arnold Schwarzenegger to former President Bill Clinton and Italian Prime Minister Silvio Berlusconi have been featured in Ashley Madison ads. Biderman said he doesn't seek permission but occasionally hears complaints, such as a letter expressing displeasure from King Juan Carlos I of Spain and a not-so-gentlemanly threat to a billboard operator over the Berlusconi ad. Both were taken down.

A longtime Bucks County Republican, State Rep. Paul Clymer, called the Morrisville billboard "tacky" and "unprofessional." He said the ad breeds ill will in an era already marked by incivility.

"People make mistakes, they do wrong things, they acknowledge them," the veteran legislator said Thursday. "Leave it to rest."

While the billboard has gotten its share of national attention - Jay Leno has riffed it - most people in Morrisville don't know it's there, because it's on a highway on the far edge of town, said Borough Manager Tom H. Bates Jr.

Mayor Rita Ledger just saw it. "Totally distasteful," she said.

"We just found it amazing that they would have a billboard in Morrisville," she said. "I thought it was a political thing."

For Biderman - who says he is happily married and monogamous, but would have an affair rather than end his eight-year marriage - there's no shortage of celebrities to plug in his ads. He said he has even offered a job to erstwhile presidential candidate and accused adulterer Herman Cain, but hasn't heard back.

In the meantime, there's always the new year to look forward to.

"The day after New Year's, we'll be beyond busy," Biderman said of his company. "People say, 'I'm going to do something for myself.' "

As for the billboard, Ashley Madison promises more of the same. A company spokeswoman said additional billboards would target key times and places on the campaign trail - such as the Jan. 10 New Hampshire primary.

Talk about swing states.

Contact staff writer Kathy Boccella at 610-313-8123 or kboccella@phillynews.com.