> By this logic, we shouldn't make or enforce laws because someday, someone can pass a law against harmless behavior.
In a so-called liberal state we shouldn't send people behind bars for political reasons, not even fascists. Sending the people that protested at the Capitol behind bars is being done as a result of politics.
You are forgetting the word "purely." If some fascist incites people to riot and innocent police officers get killed (hypothetical example), then there are strong political reasons to put the perpetrators behind bars for their crimes. Law and order is a political issue. Protection of institutions is a political issue.
The First Amendment doesn't say you can incite a riot as long as it is a political riot. That a crime is politically motivated (or politically impactful) does not somehow absolve the perpetrator.
Surely you don't believe that the only politically motivated crimes are cases of incitement...yet I think you're a bit off track anyway, for a different reason.
> In a so-called liberal state we shouldn't send people behind bars for political reasons, not even fascists
Note the "shouldn't" -- even if your point were valid, it's moot because this is a conversation about "should" not "do."
Gitlow v. New York upheld conviction based on a loose interpretation of "clear and present danger," and later Feiner v. New York held that the police can take action against speech when there is a clear and present danger. But again, none of that matters because we're not debating legal theory, nor implementation of law.
Are you suggesting that we should pardon all criminals who are motivated in part or in whole by political reasons?
Regulation, moderation, and law enforcement are always a balancing act. We can't just say that balance is an impossible dream, so let's just give up.