Threats of punching
Clinton threatens Brown
"... in one very memorable debate, Brown brought up Hillary Clinton’s questionable ethics in her Arkansas legal career, as well as Whitewater, and Bill Clinton, very theatrically, threatened to punch him in the nose."  Clinton also threatened to punch White House speechwriter William Safire in the nose, is known to have assault political consultant Dick Morris in front of witnesses.
A blogger threatens Glenn Beck
"Besides a straight jacket to keep those arms from flailing - Beck needs a good hard punch in the face - preferably a punch that would damage his vocal cords - permanently." 
A journalist threatens a blogger
"In 2009, the anchor got into a very heated argument with blogger Mike Rogers, who has helped to out many closeted gay politicians. McKelway vehemently objected to the practice, so much so that he threatened to punch Rogers in the face at one point in the conversation."