Are we forgetting the Caning of Charles Sumner in 1856? Senator Sumner (R-Mass.) was assaulted on the Senate Floor by Representative Preston Brooks (D-SC) while co-conspires Rep. Laurence M. Keitt (D-SC) and Rep. Henry A. Edmundson (D-VA) blocked other Senators from assisting in stopping the fight. Brooks' attack was in retaliation for a speech in which Sumner accused Senator (and Brooks' cousin) Andrew Butler (D-SC) of wishing to keep slaves in order to sexually force himself on slave women (this was not the first time such charges had been lobbed in the Abolition debate, and Pro-Slavery politicians would attack the sexual morals of Abolitionist in kind.).
Sumner was temporarily blinded during the attack and for the remainder of his life suffered from pain and emotional damage from the attack that today is known consists with traumatic brain injury and PTSD. In fact, during the attack, many Senators pleaded with Brooks to not kill Sumner, and the attack stained the floor of the Senate with Sumner's blood.
As it was an election year, and occured during the height of the Bleeding Kansas crisis, Republicans used the attack slogan "Bleeding Kansas and Bleeding Sumner" to call out the democrats barbarism and while Brooks challenged two more Republicans to duels, one accepted, but chose weapon of Rifles and the battleground of "the Canada side of Niagara Falls" and another refused on the grounds that such an act was barbaric and elected to highlight Brooks' further barbarism (Note: At the time, Dueling was outlawed in the United States, so the later politician was refusing on the grounds that he would not perform an illegal act... the former was a noted crack shot and knew that under Canadian law at the time, dueling was perfectly legal... Brooks did not follow through on the acceptence, citing dangers of traveling through the Northern States... but likely realized the person who challenged him was probably going to kill him and get away with it.).
For some time after the attack, several members of Congress carried weapons on them out of an abundence of caution. That said, physical attacks between U.S. legislators is very very rare, so it stands out. This is not to say that Nancy Pelosi's ripping of the State of the Union is justified, but that she merely qualifies for the "Not as Big of a Jerk as you could have been" Award.