I've heard many different theories, including Wisconsin Germans disparaged Poles as dumb, Poles were called as dumb, because they were good machinists, and people got jealous, to Hollywood, and the media promoting it. to Nazi Germany promoting dumb Polak jokes. One thing is true, I don't think such politically correct joke would be so for Blacks, Hispanics, Asians, Muslims etc. etc. Just look at how Papa John was treated for just saying the N word, not disparagingly, but just as a word that could not be said. (Hardly offensive) Especially in comparison to dumb Polak jokes. It seems people think dumb Polak jokes are okay, because they're White Catholics. Even though Poles were also murdered by multiple millions, in WW2, WW1, The Partitions of Poland, and the Deluge combined totals could really support that 8 + million Poles had been killed. But, that doesn't matter, so long as they're getting back at Whitey oppressor, by lashing out at Polish people.