I think you have better chances when protesting WITH them and pushing the Pizzagate argument. This shows that Pizzagate is non-partisan and might convince anti-trumpers to look into it as welll..

For example: Imagine if you were one of the anti-trump protesters and there is one guy that is obviously not on your side of the argument shouting Pizzagate. Would you feel inclined to start looking into it? But what if the guy standing next to you screaming the same thing ALSO talks about Pizzagate? then things start to become interesting...