In 1968, the Democratic National Convention was in Chicago, and the putative nominee Robert Kennedy was assassinated. Chicago rules are not to be regarded lightly.
You are implying a connection between the Chicago convention and the Bobby Kennedy assassination that seems to be pretty much of a stretch.
Kennedy was assassinated in early June in Los Angeles, on the night of his California primary victory. The purported assassin was Sirhan Sirhan, an Arab who supposedly killed Kennedy because Bobby was pro-Israel. It's almost impossible to connect the assassination to Chicago or the Daley machine or "traditional" organized crime.
The convention took place in Chicago in late August, and was punctuated by violent street clashes between radical left demonstrators, protesting the nomination of establishment candidate and Vice President Hubert Humphrey, and Daley's Chicago police force outside the convention hall.