John McCain's presidential campaign is threatening a lawsuit against the National Enquirer over a print edition story the tabloid alleging that Gov. Sarah Palin has had an extramarital affair with her husband's business partner.

Sarah Palin had an extramarital affair with her husband's business partner?

"The National Enquirer's coverage of a vicious war within Sarah Palin's extended family includes several newsworthy revelations, including the resulting incredible charge of an affair plus details of family strife when the Governor's daughter revealed her pregnancy. Following our John Edwards' exclusives, our political reporting has obviously proven to be more detail-oriented than the McCain campaign's vetting process. Despite the McCain camp's attempts to control press coverage they find unfavorable, The Enquirer will continue to pursue news on both sides of the political spectrum," the paper tellsThe Huffington Post

"The smearing of the Palin family must end. The allegations contained on the cover of the National Enquirer insinuating that Gov. Palin had an extramarital affair are categorically false. It is a vicious lie," said McCain senior adviser Steve Schmidt. "The efforts of the media and tabloids to destroy this fine and accomplished public servant are a disgrace. The American people will reject it."

"Whatever the merits of the whole Edwards love child story, are we really supposed to believe that one of America's most famous trial lawyers wouldn't sue a publication that printed defamatory and slanderous lies about him? Also, it's worth pointing out that while the Enquirer may or may not be scrupulous in its choice of stories -- that's in the eye of the beholder -- it is pretty scrupulous about its facts. They win lawsuits. They've broken a host of stories the MSM guys couldn't."