Thank you both for your ideas! I know that while researching this topic the First Amendment does not protect some specific types of speech, specifically one that I came across was:
Government may prohibit the use of 'fighting words,' which is speech that is used to inflame another and that will likely incite physical retaliation. Likewise, language that is meant to incite the masses toward lawless action is not protected. This can include speech that is intended to incite violence or to encourage the audience to commit illegal acts. The test for fighting words is whether an average citizen would view the language as being inherently likely to provoke a violent response."
I'm aware that communication about issues such as sexism and racism does not always elevate to "fighting words." But, how could the aff defend the importance of the discussions of these issues in society if the neg brings up that it's difficult to measure what is considered hate speech and what is not, especially in heated conversations about topics like that?