US democratic party is not a flock of angels... but they're certainly not idiots.
The democrats are roughly center-right when you look at it in comparison to major countries across the world. See e.g. https://qz.com/1748903/how-2020-us-democratic-candidates-com...
The only one that you can make, based on the data, is that US politics trend much further right than many other places, and that talking about "Democrats" and "the left" in the same breath doesn't make any sense in a global context. They just aren't.
And I think that is very relevant when you want to talk about US politics. It defines the available spectrum.
Why would there be? These are ridiculous goals. North Korea has open doors if you want to defect. I've heard it's pretty nice over there.
That's a pretty loose definition of 'major'.
Parliamentary systems sound pretty shitty then - keep in mind the Golden Dawn, UKIP, and any one of the perennial "let's deport all the Roma" parties also counts as a major political party under your definition.