"These sorts of things, I think, invite the kind of toxic rhetoric that can lead unstable people to believe this is an acceptable response," Durbin said Sunday on CNN.
Republicans were especially sensitive to suggestions that their side of the political spectrum was contributing to a more poisonous political environment.
Sen. Lamar Alexander, R-Tenn., noted Sunday that the suspect in the Tucson rampage was connected to Internet postings that included Marxist and Nazi literature.
"That's not the profile of a typical tea party member, if that's the inference that's being made," he said on CNN.
To be sure, combative language in politics is not the province of a single party. It was Obama who declared during the 2008 presidential campaign, "If they bring a knife to the fight, we bring a gun." And Sen. Joe Manchin, a West Virginia Democrat, ran ads during last year's campaign that portrayed him with a high-powered rifle, placing a cap-and-trade energy bill in the crosshairs and blasting it to pieces.
The Tucson shooting could also result in hypersensitivity, where lawmakers take any partisan comment as an invitation to incite a fight.
"The danger in this is that people misread it and so the first time that someone makes a statement that is partisan, it's condemned as inappropriate," Jamieson said.
Experts say angry political language is made all the more prevalent by the Internet and opinion-driven cable television, amplifying the sense of confrontation. Jamieson says she doesn't believe current Congresses have been more uncivil than past one.
"But the media culture has given us access to incivility that probably was there all along but didn't have that much accessibility," Jamieson said. "The consequence of broader exposure is that it becomes normalized."