"Character counts and our values matter," McDonnell told a crowd of Mitt Romney supporters in announcing his endorsement of the former Massachusetts governor and current front-runner for the GOP presidential nomination, The Hill reported.
Gingrich has been dogged by an interview his second wife, Marianne, gave to ABC News this week, in which she said he asked her for an "open marriage" so he could continue his affair with Callista Bisek, who was a congressional aide at the time and is now his third wife.
"I just know from my past years of getting to know Mitt … he put family and traditional values at the top of his list," McDonnell said.
Romney is banking on McDonnell's endorsement to give him a much-needed lift after polls show his lead slipping in South Carolina in the days before Saturday's primary election.
Celebrity Families of 2014 [PHOTOS]