The worst feeling is being faced by oppressors. The old preacher who's damning you to hell for enjoying gay sex. You're out there, speaking your mind, exercising your right to free speech. And so are they. There is a great divide between the liberal and conservative view points. Where acceptance and tolerance are ridiculed and exclusivity is deemed necessary.
You're getting your point across. Don't be an asshole while you are doing it. Obviously there is no need for violence in American protests. We can hold up enough signs and sing loud enough, that violence just doesn't seem necessary. Respect the authorities that are there to protect everyone, from the assholes. And go into the situation with a heartfelt purpose and the goal of promoting your ideas. People can be convinced to see your side, but only if you are rational and respectful with your delivery.