Heckling and booing of politicians is considered a national sport, but Wednesday night's outburst by Rep. Joe Wilson during President Obama's healthcare speech on the floor of the House may have reached a new low, according to congressional historians.
"It really does tell you how low we've sunk when it comes to common courtesy," said Norman Ornstein, a political scientist at the conservative American Enterprise Institute.
"This is not something we've seen before during a presidential speech," said Ornstein. "Yes, we've had booing and hissing, but yelling in the middle of a speech 'you lie,' that's something different."
According to congressional expert Steven Smith, other more subtle signs of disapproval – rather than audible exclamations – are common in Congress and have come to be expected during major policy speeches.
"What has happened over the last quarter century is that the minority party – whether it's the Democrats or the Republicans – have become increasingly childish," said Smith. "They will sit on their hands and not applaud during obvious applause lines and react vocally to things they don't like."
"They'll have smirks on their faces, little orchestrated developments like last night's members holding their own copies of health plans in the air during the president's speech or will hiss or boo," said Smith.
Wilson's outburst was the latest in a series of increasingly testy comments on both sides of the healthcare reform debate that began with town hall meetings around the country erupting into yelling matches that were marked by accusations -- from both sides -- of misleading deceptions and wildly inaccurate statements.
Wilson's heckling was also an indication of how hard it is to change the tone in Washington, a campaign promise made by both Obama and his predecessor President George W. Bush.
Bush was no stranger to hecklers. During his 2005 State of the Union address, Democratic members of Congress booed him loudly as he spoke.
Bush's father, former president George H.W. Bush, wasn't booed in the halls of Congress, but he came face-to-face with hecklers in 2003 when he received an honorary Doctor of Law degree from Central Connecticut State University as students screamed "mass murderer," referencing his war policies in Iraq.
In 1998, then-President Bill Clinton was bombarded with insults during his first public appearance since admitting an affair with Monica Lewinsky. Audience members screamed at Clinton to resign and called him a "liar" while the former president spoke at a Massachusetts' hall.
Earlier in his presidency, Clinton was berated by hecklers for being a "draft dodger" during a Memorial Day speech in 1993.
More recently, Sen. Harry Reid, D-Nev., accused former President George W. Bush of lying about plans for dumping nuclear waste and later referred to him as a "loser" during a speech to a group of high school students.
And Speaker of the House Nancy Pelosi, who was visibly taken aback by Wilson's comments last night, has had her own share of hecklers. The anti-war activists known as Code Pink screamed at Pelosi during a 2007 speech, demanding that the government bring troops home from Iraq.
Despite those incidents, Smith says that when considering more recent instances of outbursts toward politicians, this behavior by Wilson and others really isn't all that bad.
"In a broad historical perspective, these events are still reasonably civil," said Smith. "We have plenty of childish members of Congress and that's unfortunate, but by and large we have a pretty civil and politically clean place compared with the past."
The 19th century was known for duels between politicians, even brutal fist-fights on the floor of the Senate.
In 1856, Sen. Preston Brooks, D-S.C., attacked Sen. Charles Sumner, R-Mass., after a speech on slavery during which another politician from South Carolina was criticized.
"He beat him so badly that Sumner was lying on the floor, bloodied and unconscious," said Julian Zelizer, a congressional historian at Princeton University. "These kinds of encounters were not uncommon in the first part of the 19th century."
"There have certainly been moments of classic, tough speeches delivered on the floor where members of the opposition are murmuring unhappily," said Zelizer, "But this was particularly harsh."
Mickey Edwards, a former GOP congressman from Oklahoma, said that even though presidents in the past have been heckled, rules and expectation of proper behavior change entirely when it happens on the floor of the House.
"Presidents are not popes, they can be criticized and called on to be accountable," said Edwards. "But you do not do that on the House floor."
"In our system you do not do that and I can't remember any case where someone actually shouts in the middle of a speech by the president. You can't even do that to a member of Congress," he said.
According to Edwards, congressmen are bound by strict rules regarding their behavior, including being prohibited to sit on a desk while they address the chamber and are required to wear a necktie.
"There are rules of civility and decorum that are supposed to keep it a place with mutual respect that allows a workable democracy, and when you turn into a shout fest the whole process breaks down," he said.