Why "we can’t have a rational gun debate"

From the Iowa State University Daily:  Snell: Waking the dragon — How Feinstein fiddled while America burned - Iowa State Daily: Opinion

I’ve come to realize after the Sandy Hook shooting that the reason we can’t have a rational gun debate is because the anti-gun side pre-supposes that their pro-gun opponents must first accept that guns are bad in order to have a discussion about guns in the first place. Before we even start the conversation, we’re the bad guys and we have to admit it. Without accepting that guns are bad and supplicating themselves to the anti-gunner, the pro-gunner can’t get a word in edgewise, and is quickly reduced to being called a murderer, or a low, immoral and horrible human being.