Another question on this ...
Would you agree that in a broad sense we have a tendency to revert to racism when we run out of good arguments to support our opinion of a specific topic ?
While your statement may have merit in at least some instances, try to think of it as an extension of something like resorting to swearing. THe person in the debate who resorts to name-calling, cussing, or the "serious stuff" racial slurs, is the one who has just lost the argument. It is thus the action of a loser and weak debater more than it is an "ingrained" responsee by people in general.