I am not sure the group that thinks American Imperialism has killed millions is significant in American politics. Perhaps here on Lemmy there are quite a few people who rightly say this, but the vast majority of Americans reject this thought outright.
I view it as one group who is fine with the status quo so much they will fight to keep it that way. They are resistant to change and feel that the strong hierarchal orders are good and that people have their place and should stay there. They are a strong minority.
You have another group of people who don't really care and kind of just go where the wind takes them. They don't have particularly strong political beliefs. They are mostly self serving but generally good natured. These people are the majority.
You have the last group of people who are against the status quo for a myriad of reasons. They embrace change and are resistant to hierarchal structures. They are not really organized as they are incredibly diverse in their reasonings and are generally a weak minority.
I think the annoying part comes from the lack of critical thought and introspection. There are so many good ways to solve our problems we have never even thought of. There are solutions to moving forward and we absolutely have to find them.