"Mike," the man Knight confronts, has a firm grip on the congressman's hand as he says, "You told me you didn't vote for amnesty, and you did. I looked it up on the Internet. You lied to me." Then Mike forcefully pats him on the shoulder. Knight approaches him. "Mike, if you touch me again," he says, "I'll drop your ass." "I shook your hand!" Mike protests, somewhat disingenuously.
The protesters were angry about their perception that Knight had voted in favor of "amnesty" for illegal immigrants. In this case, the bill at issue was H.R. 240, the legislation that ping-ponged across Capitol Hill earlier this year that would, in its initial iteration, have revoked President Obama's executive orders on immigration as part of approving funding for the Department of Homeland Security. As originally passed by the Republican House, the bill would have met the protesters' concerns; it received a "yes" recommendation from the conservative Heritage Action. Knight voted yes on that bill.
Knight's point to the protesters is that the bill needed to be amended for passage in the Senate, or DHS would shut down. "How many votes do I need in the Senate," he asks. "Sixty," someone replies. Since the Senate needed Democratic support to pass the measure, and since Democrats opposed blocking the executive action, the Senate took out the immigration measure and sent the so-called "clean" funding bill back to the House.
Then Knight's version goes sideways. "So the Senate stripped out the amnesty," he says -- with protesters interrupting to say it stripped out the "defunding of amnesty." They're correct, if that's how you choose to frame it. The bill that came back to the House (and which got a "no" recommendation from Heritage) did indeed get Knight's vote. He was one of 75 Republicans to support the measure.
Knight's argument might be that he opposed "amnesty" in the sense that the protesters mean. But that's not the argument he makes. He's debating how he voted on the funding bill which, in the end, was contrary to what the protesters wanted.
You should not smack a member of Congress on the shoulder while backed up by a large angry group of people. Members of Congress, however, should not physically threaten a protester, constituent or not. Or, for that matter, misrepresent key votes.