They called on them with dog-whistles of armed revolution, with what they knew, but their targets didn't, were metaphors of enemies of the nation at the controls. Minnesota Republican Rep Michelle Bachmann calling for some sort of press-run Neo-HUAC investigating Democratic Congressmen for being "Unamerican." Sharon Angle telling her supporters that Mexican drug lords were pouring over Nevada's border with Mexico (I know, but I'm not sure she did, and less sure her followers did, that Nevada doesn't have such a border) with the collusion of Harry Reid, and if she couldn't defeat him at the polls, they'd have to "remedy" the situation by exercising their Second Amendment rights. There's more, an entire invented scenario of "real Americans" being reduced to some for of rebellion to "take their country back" from "enemies" who had somehow illegitimately seized power.
There's no serious doubt that this is deeply racist. The country didn't need to be "taken back" until it was "in the hands of" a black man, who the Teabaggers go through all sorts of gyrations to delegitimize: He's Muslim, he's Kenyan, he's a Socialist, he's a Nazi.
These were the troops conscripted to fill the ranks of the Right's political army of voters: The credulous, the uncritical, the simpleminded, easily led, easily spoon-fed the idea that someone they weren't comfortable with anyway because of their own innate prejudices was responsible for their sorry lot in life. They were shown an enemy, and told to fight-fight-fight to the very last to defeat him. Of course, the weapons with which they were supposed to fight were simply disruption and votes. No, nobody worth listening to _really_ thinks the idea was to get them to kill Liberals.
But that's the problem with crazy people: They're crazy. As Fox Mulder asked the guys who made a deal with Satan to straighten out their school system, "Did you really believe that you could call up the Devil and ask him to behave?"