The riot isn't seen in the movie, but it is alluded to. He has this one speech that gives a great sense of texture and paints a picture of what was happening in Harlem then.
“The difference today is that, in both parties, the very extreme elements control the nomination process.”
“By overhauling current rules and speeding the entry of competitors in the market, we encourage competition and provide our constituents with new choices and cheaper bills.”