All that Constitutional sanctity and American exceptionalism horseshit that was rammed down our throats growing up is really coming back to bite us on the ass.
People know we have a constitution, and they know that it's important, they just don't know specifically what's actually in it, the limits of what's in it, and how the things that are in it can be amended. They also don't seem to realize that a constitution isn't some magical thing unique to the USA.
Thinking that America is the greatest, most infallible nation on earth has just led to regressive thinking and has made it impossible for anything to actually change or get better. A theme that was always hammered home to me was "America might not be perfect, but we're still the best and American style capitalism is still the best for everyone"... Any suggestion that our policies or attitudes should be different and/or more in-line with how the rest of the world does things (when those things are proven to work) is met with belligerent hostility and ignorance. They don't even have a frame of reference to what they're arguing against.