But in an appearance on CNN's "State of the Union" he also cautioned against exaggerating the degree to which sharp-tongued political rhetoric contributed to the Arizona incident.
"Of course we want civility instead of incivility, and of course we don't want violence. But I think in all of the talk about this we have to be very careful about imputing the motives or the actions of a deranged individual to any particular group of Americans who have their own political beliefs," Alexander said. "I mean, what we know about this individual, for example, is that he was reading Karl Marx, and reading Hitler and burning the American flag."
But after an election cycle in which Nevada's GOP Senate candidate, Sharron Angle, spoke about "second amendment remedies" for defeating her opponent and others brandished weapons in their own campaign ads, including West Virginia Democrat Joe Manchin, who used the climate change bill for target practice, as well as many more who simply channeled anti-government rage, the outcry is perhaps not surprising.
In the group's e-mail message, Move On also circulated a petition to its members calling on lawmakers in Washington and well as television and cable news networks "to put an end to the hateful rhetoric and all overt or implied appeals to violence."
"We must put an end to the rhetoric of violence and hate that has exploded in America over the past two years," Ruben wrote.