You never see Yankee jokes because for the most part they are a protected sub group (except for the poles and WASPs). The poor white southerner is one of the few left that can be sterotyped and ridiculed. Maybe because he is such an independent cuss who will fight at the drop of a hat to protect his rights or when some lisping sissy gets face to face with him and throws an insult or some newperson tells him he is too ignorant to decide who to vote for.
Just an opinion.
BT