Mike Tyson has threatened to throw him down the stairs. Cher discovered him in her closet. Madonna has invited him behind closed doors to give him the first glimpse of her in chains on tape. And most recently, his organization helped expose the secrets of a former presidential candidate.

Barry Levine, the executive editor of the National Enquirer, spoke with a small group of School of Media and Public Affairs students last week about the notorious tabloid’s vigilant research into the John Edwards scandal and why its coverage ought to earn a Pulitzer Prize.

It could be one of the biggest political scandals of the decade, but Levine said it all began with a phone call. Two years ago, the Enquirer’s office received an anonymous call stating that Edwards, then a Democratic presidential hopeful, was cheating on his cancer-stricken wife with a campaign videographer named Rielle Hunter.

Levine said every source comes forward for a unique reason. He says some come for revenge. Others come forward for cash.

Checkbook journalism – the practice in which an organization pays its sources for information – distinguishes the Enquirer from other organizations. Levine said he defends his paper’s choice to pay sources for information, saying there is no simple formula of writing a check and getting a story.

“I wish I could’ve just written a check to crack this story,” he said.

Enquirer investigators began scrutinizing Edwards’ movements on the campaign trail. Levine said they noticed him missing at certain, inexplicable times. He was showing up late to important meetings.

“We never let anything go, not even a morsel of a one-line tip,” Levine said.

Levine said his team often administers a polygraph to sources, using the same technology as the FBI and CIA. Sometimes they ask a witness to sign an affidavit or a contract obligating the source to speak for the Enquirer in court if a published story leads to a lawsuit.

“A question we always asked is, ‘What’s the chain of information?’ ” he said. Enquirer writers concern themselves with the likelihood of a person actually knowing his or her statement is true, Levine said.

A few months into the Edwards investigation, the Enquirer received another tip that would change the dynamic of the entire investigation – Hunter was not only John Edwards’ mistress, she was also pregnant with his child.

Levine sent a team to North Carolina to get a shot of Hunter pregnant. Finally, in December 2007, Levine received a call that one of his teams had spotted her walking into a local hospital. Redirecting everyone to the scene, they discreetly photographed the woman from afar as she left the hospital and got back into her car. After comparing the image to others of Hunter, as well as images the team caught of Hunter at a grocery store, Levine said the team knew its efforts had paid off.

Days after the Enquirer published the photo, Andrew Young, another Edwards campaign aide, released a statement that he and Hunter had been involved for several months and that the child she was carrying was his. His statement was sufficient for most, and the heat was temporarily off of Edwards. But Levine said he noticed too many inconsistencies to be fooled – Hunter traveled with Edwards on the campaign trail, while Young only worked the headquarters in North Carolina. And Edwards, despite Young’s statement, still refused to publish his cell phone records.

Then in July 2008, Levine said he received a call that Edwards was flying to meet Hunter in a hotel in Beverly Hills. Enquirer reporters staked out in the lobby of the hotel where they confronted Edwards as he left. Moments later, Levine said, Enquirer reporters were standing outside the door of the lobby’s men’s room with Edwards crying on the phone saying that the Enquirer had caught him.

Days after, Edwards publicly announced his affair with Hunter on national television, although he still denied paternity of her child – something he finally admitted last month.

Richard Leiby, the SMPA professor who invited Levine and an editor of the Washington Post, said the Enquirer’s coverage of the Edwards scandal “has elevated its credibility enormously.”

Levine said many other reputable newspapers like the New York Times and the Los Angeles Times have admitted their mistake in not pursuing this story to its end.

“The gates are now open,” Levine said. “Anyone who puts in the time and resources will get the story.”