"After this, I think he should do himself and everybody a favor and just step to the sidelines. He is not qualified — not psychologically qualified to be mayor of the city of New York," King said on CNN's "State of the Union."

King criticized Weiner for running in the first place when he knew more lewd exchanges were likely to surface, including graphic conversations and photos he sent after resigning.

"There's a real pathological problem here with him," King said. "I mean, how he could be out there knowing all this information was going to come out."