[cnn-photo-caption image= http://i2.cdn.turner.com/cnn/2008/images/08/19/art.portman.gi.jpg caption="Rob Portman played the part of Obama in McCain's debate prep."]
OXFORD, Mississippi (CNN) - After days and days of denials that they had anyone playing Obama in debate prep sessions, two McCain campaign aides admitted to CNN they were using a stand-in for the Democratic nominee: former GOP congressman and OMB director Rob Portman.
Portman has been playing Obama in mock debates, including a two-hour session Thursday night in McCain's Virginia apartment, and one at an Oxford high school hours before tonight's debate.
Ironically, in 2000, Portman played Joe Lieberman in mock debates for then VP candidate Dick Cheney.
Now Lieberman is a close friend and supporter of McCain's, and a regular on the road with him.