However, the report said, representatives of the Palin campaign were unable to specify which Obama/Biden Democrats the campaign was referring to when it leveled the charged in a fundraising solicitation sent out Thursday.

The letter said "the Obama/Biden Democrats have been vicious in their attacks directed toward me, my family and John McCain."

In response to a request for specifics, the Palin campaign told ABC that an Obama campaign spokesman had said Palin was a supporter of one-time presidential candidate Pat Buchanan, a former Nixon White House speechwriter who currently works as an analyst for NBC News.

Palin and her family have been the subject of numerous stories on the Internet, but Obama and Biden have said family matters are not appropriate subjects for the campaigns to address.