The video, obtained by The Cut, was shot in an Iowa fire station moments before Matthews interviewed Clinton as she sought the Democratic presidential nomination.
Matthews apologized for his remarks in a statement Friday, and said his comments were "made in poor taste during the height of the Bill Cosby headlines".
Before interviewing the candidate, Matthews made a comment about giving her a "Bill Cosby pill". "I realize that's no excuse". " He once called Clinton "witchy", and has repeatedly questioned whether her gender could have a negative impact on her ability to make decisions. I deeply regret it and I'm sorry", he said.More news: Salah to be fit for City clash
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He wondered aloud in 2005 if the military would "take the orders" from a female commander in chief, like Clinton, Jezebel reported. He pinched her cheek after an interview in 2008, and suggested that her political career had been advanced because her husband had "messed around".
Two sources familiar with the situation told The Daily Caller that Matthews paid $40,000 to settle with an assistant producer on his show, "Hardball with Chris Matthews", in 1999 after she accused him of harassment.
MSNBC disputed the report, saying the settlement was "significantly less" than the reported amount. Matthews was reprimanded, an MSNBC spokesman said at the time. Based on people who were involved in the matter, the network concluded that the comments were inappropriate and juvenile but were not meant to be taken as propositions. "Precious waters?" Matthews was seemingly referring to Clinton.