That led to the pro-Cheney contingent (which it should be said greatly outnumbers the opposition) to shout the hecklers down with the familiar "USA, USA" chant.
It was all very odd, especially considering that when Cheney appeared as the "surprise guest" at last year's CPAC he was greeted with the kind of cheers generally reserved for a rock star.
But Team Paul -- whose numbers appear to have grown at CPAC in 2011 -- were not going to let that happen this time around.
"Uh, Defender of the Constitution?" Justin Bradfield of Maryland scoffed when I caught up with him after he walked out of Rumsfeld's speech. "Let's see: he expanded the Defense Department more than pretty much any other defense secretary and he enforced the Patriot Act."
"[Speaking] as a libertarian, that's not really the type of person who should be getting Defender of the Constitution," he added.
Bradfield said the moment showed that "half" of CPAC this year is libertarian, which means his side is winning in the civil war between "libertarians and right-wing conservatives."
"We're loud," he said.