It's not political bias like Republicans will say either...
Because the ACLU is having the same fight with the DNC too.
Chicago is denying protest permits, so the protests are "illegal" and they can beat people into submission.
If you're interested in protesting, the ACLU has resources for what you need to know about both sites
https://www.aclu.org/news/national-security/know-your-rights-dnc
https://www.aclu.org/news/national-security/rnc-know-your-rights