I can guarantee you that approximately 0% of people who are going to protest within the next few days are expecting trump to just be like “oops! Y'all got me! I’ll resign” because that’s not the point. Protesting can’t automatically undo what has already been done, but it does send a message of distaste, shows that people will make noise if they sense injustice, and signifies that citizens will continue to protest as worse things (may) happen. It’s a response, not a plea