gandalf: I was going to respond to Casca and his lionizing the Nazis with a quote from Nietzsche (“Whoever fights monsters should take care not to become one”), but I think it is more apropos here.
Why is dialogue, discourse and decorum important? Because it helps separate you from the people you are battling. Another great expression is the one from Booker T. Washington: “One man cannot hold another man down in the ditch without remaining down in the ditch with him.”
Wingnuts are not a just a recent happening. We have always had them. But responding with the same weapons simply coarsens the dialogue, demeans us a civil, thinking society and plays right into their hands (whether they are Dems or Repubs, right or left, etc).
