Mass protests probably will be a catalyst to change, but in the end, real power change in Washington would have to come through the political process, and in a two-party system in which one of the parties is completely in thrall to a foreign power, that leaves only the party that is not. Unless you mean a new political system ruled by mass protests of the people, which, who knows that would even work.
I also agree a substantial event would have to trigger the mass protests, but I don't think we are all that far from seeing that.