in chapters 19-30, The con-men are two of the vilest characters in Twain's text.
The Duke and King are con-men. Initially huck finds them entertaining. Their banter is ridiculous and their con-jobs seem innocent enough. Their enactment of Romeo and Juliet on the raft is quite comical. Still, there is an undercurrent of nastiness to them. Huck discovers that they have no concern for anyone else (they try to get Jim captured) and that their is hurtful fall-out wherever they go. After their "hijinks" there is little that is funny about who they are and what they do. I think Twain is attacking human greed, deceit and lack of empathy. These two guys, although humorous, seek only self-satisfaction often at the expense of others and even each other.
