Former Republican Rep. Livingston: "Newt is volatile"

With friends like these, Newt Gingrich should probably follow President Harry Truman's advice and get a dog.

Former Rep. Bob Livingston, of Louisiana, addressed a small crowd in Charleston on Friday, acting as a surrogate and supporter of the former House speaker. Livingston was gently breaking the news that Gingrich would not be speaking to the group after all. Asked by reporters why Gingrich was a no-show, Livingston was surprisingly candid.

"Newt is volatile, to say the least," he said -- not the optimal endorsement for a presidential candidate who has been assailed by his Republican rivals as a chaotic and disorganized leader.

Gingrich canceled an event Friday morning and avoided talking with reporters after his second wife, Marianne Gingrich, said in an interview with ABC News that Gingrich confessed to a six-year affair with a congressional aide and then asked her to engage in an "open marriage" so that he could keep his mistress. The former mistress is now his third wife, Callista Gingrich.

The candidate visited a children's hospital, but also declined to answer questions from journalists. He took a walking tour of the hospital, and Callista read the children's book she wrote, Sweet Land of Liberty, to some of the facility's young patients.

In a Thursday night debate, Gingrich denied ever asking for an open marriage -- and slammed CNN debate moderator John King for bringing up the issue.