Their country was founded precisely to stop both.

The state was founded by genocidal enslavers. That's what it is despite this kind of imperial mythology.

Their constitution was almost utopian for the time

For rich pale skinned bros.

How the american middle class could let this happen is baffling.

Always has been and it's not very baffling if you have a realistic understanding of history, colonialism, genocide/slavery, capitalism, etc.