I managed to dig up this gem from his 1986 race for US Senate, as quoted in the Tucson Citizen:
Did you hear the one about the woman who is attacked on the street by a gorilla, beaten senseless, raped repeatedly and left to die? When she finally regains consciousness and tries to speak, her doctor leans over to hear her sigh contently and to feebly ask, ‘Where is that marvelous ape?'
I find rape jokes are always a sign of class, don't you?
Pretty disgusting if you ask me. Here's the pdf.