Just to note that this has now been addressed by Cecil, in a “Straight Dope Chicago” column: http://chicago.straightdope.com/sdc20090514.php
Consequently, I’m marking the title and moving this to the other Chicago forum.
Lil Richie learned his manner from his mentor, Da Mare, Sr. Dan Sorkin, a local DJ and frequent parodist of the mayor and his minions used to do a bit in which he said, in his finest Richard M. voice, “Look, dere is no soutwest side bloc. Dere never has been. An anyways, dere a nice bunch of guys.”