The purpose of a protest in general should not be to affect the people in power, it should be for enpowering and bonding the people to further enact post-protest. A moralle boost, a conversation starter, an ignition to call more people to action. Having sayd that, a very successfull protest does affect the upper ones, only temprorarily and tactically. A policy maker will still want to make X move, but ever so slightly delay it or figure out a differnt narrative to bring it back some time later.