Does free speech exist in USA? Can you say what you want?

You have the right to say whatever you want, but at some point you are held responsible for what you have said. The example that gets paraded out the most is yelling "fire" in a crowded theater. Speech that causes injury to others is something that limits what is appropriate to say. I guess the actual charge if there was one would be inciting civil unrest. The reality of the US court system and laws is that you can sue anyone for anything in a civil court, The current idea in politics is to censor the speech of the opposition, it really doesn't matter which side you are one, the other side is trying to control what gets to be aired in public forums.