He said it was not impossible, however, for many Malays to support the DAP candidate as history had proven that the Malays were easily duped by such a move by DAP.
"The action is mere window-dressing and no high hopes (placed on the candidate). If she wins, it's victory for them (DAP)," he said at the 'Chancellor's Talk' programme here.
Dr Mahathir was referring to candidate Dyana Sofya Mohd Daud, 27, who was nominated by the DAP to challenge Gerakan president Datuk Mah Siew Keong in the May 31 poll.
Dr Mahathir also expressed his disappointment that Dyana Sofya was the daughter of long-time Umno supporters.
"It's not a bother if the candidate comes from a pro-opposition family as from small, she would have been taught to hate Umno.
"As parents, Umno members should tell their children about Umno, its history and what it has done (for country and people), otherwise when they grow up, they will do as they please," he said.