Way back in 1972 or so, I had this professor that made some statements similar to this. Some dumb kid did something similar to what you did TH2006. Only he didn't leave class.
After the Prof finished berating him, he calmly looked at the Prof and then the class, and said, "In April of 1775, General Gage ordered Col. Francis Smith to proceed to Concord, to seize and destroy the munitions stored by the militia. We know from history, that though outnumbered, the Minutemen beat back the British. All the way back to Boston. The minutemen were rebels and traitors to the Crown. These rebels became American Patriots, because we ultimately won the war."
"That sir, is the difference between you and I. You see a rebel, instead of an American Patriot. You see a moldy piece of parchment, whereas I see the embodiment of our hard fought rights."
That dumb kid did this for the entire semester. He was a thorn in the professors side. Got an A out of that class, he did.
The object, of course, is to stand up for what you believe.