Here is video of a contentious exchange between Sen. Arlen Specter and his Democrat Primary opponent in the Pennsylvania Senate Race - Rep. Joe Sestak. The two appeared in a debate together on May 1, 2010.
Specter demands an apology from Sestak for calling him a "liar." Specter said he has stated "facts" about Sestak's military service record when he has pointed out that Sestak was "relieved of duty" for the kind of "climate" he created under his command.
Strangely, Sestak appeared to stick to a script in his immediate response to Specter, and really did not address Specter's demand for an apology.