To take up a firearm against a political candidate or position you disagree with. Coined by the media in response to perceived violent rhetoric in the 2010 election campaigns. A variant on Senate candidate Sharron Angle's assertion during a debate that her opponent, incumbent senator Harry Reid, needed to "man up."
"Sure, the Republicans use homophobia to "gun up" thier base but it's not working very well any more, the noticeable exception being old people." - David Brock, CEO of Media Matters of America, on Hardball with Chris Matthews, January 12, 2011