USians can be a weird bunch. I swear there's like this thing of simultaneously having very strong opinions about how things should be (because of basically believing they live in a democracy) while also being shy of getting directly involved in the process of stuff. Like viewing themselves more as arbiters who are consulted occasionally than direct participants in society. Obviously doesn't apply to everybody, but seems like there's something consistent to it that is reflected in this kind of poll. (And I am not trying to say this from on high, I am USian myself and may have some of this in me.)