As stated in the New York Times:
House Democrats intend to pursue a formal resolution admonishing Representative Joe Wilson for his outburst against President Obama during the president’s speech to Congress on Wednesday night unless he apologizes on the floor.This kind of behavior wouldn't be tolerated in a high school assembly toward a principal, let alone toward the President of the United States. It is really time for the Republicans to stop the lying, stop the ridiculous behavior, and stop acting like children. It is unacceptable and appalling behavior. Once and for all, learn to discuss and respectfully disagree - not heckle and blatantly disrespect - our president. Enough is enough.
Senior aides said Friday that the leadership had decided that the behavior of Mr. Wilson, a South Carolina Republican, in shouting “You lie!” merited some response by the House even though he had issued an apology and expressed his regrets to the president through Rahm Emanuel, the White House chief of staff.“It is a clear violation of the rules of the House, and it needs to be resolved on the floor of the House either by an apology or by a resolution,” said Brendan Daly, a spokesman for Speaker Nancy Pelosi.