Final answer:
The politician may not be protected under the First Amendment because incitement of a criminal act is not protected speech.
Step-by-step explanation:
The politician's defense that their words to rally supporters are protected under the First Amendment of freedom of speech may not hold up in court. While the First Amendment does protect most forms of offensive and unpopular political speech, it does not protect incitement of a criminal act. Inciting an insurrection and calling for people to grab weapons and storm city hall can be seen as a direct promotion and a genuine threat, which are not protected under the First Amendment. The authorities' actions in arresting the politician outside before any altercations happened indicate that they considered the politician's words to be a clear and present danger.