Trump has been very clear with his words and actions that his administration is going to do everything it can to make life miserable for anyone who is not an upper-class straight white cis male.

If we stand up and make our opposition visible, it sends a message- both to Trump and his supporters, who will likely ignore it, but also to the folks who will be victimized by his administration, to let them know that they are not alone and that the majority of the country does not support Trump's behavior.