An individual and a group applied to the Chicago Park District for permits to hold rallies advocating the legalization of marijuana. The Park District, a municipal agency, required a permit to conduct a public assembly, parade, or other event involving more than 50 individuals. Applications for permits had to be processed within 28 days, and denials had to be clearly explained. Denials could be appealed to the general superintendent and then to the courts. The Park District denied some of the permits for pro-marijuana rallies. Those denied filed suit, claiming the Park District permit rules were unconstitutional.
a. What constitutional challenge was raised by the plaintiffs?
b. Decide the case. Explain.