Carly Fiorina was ready when CNN’s Jake Tapper asked her to respond to criticism about her record at Hewlett-Packard during last week’s Republican debate.

Looking intently into the camera, Mrs. Fiorina said a prominent venture capitalist who pushed for her firing at Hewlett-Packard in 2005 had recently taken out a full-page newspaper ad saying that he had been wrong to do so and that she had been “a terrific C.E.O.”

What Mrs. Fiorina did not mention was that the ad — which cost roughly $140,000 — was paid for by the “super PAC” supporting her presidential candidacy. The same group, Carly for America, has gathered video footage of the venture capitalist, Thomas J. Perkins, praising Mrs. Fiorina, and it could be used in television or Internet ads in the weeks ahead.

The moves are part of an extensive effort by Mrs. Fiorina and her supporters to redefine her rocky business reputation and fend off attacks on her as an unfit and heartless executive. Such accusations helped doom her 2010 Senate campaign in California. Democrats called her “Carly Fail-orina,” and the incumbent, Senator Barbara Boxer, depicted her as the face of corporate greed.