I recently watched videos of Bernie Sanders, who americans call left-wing, and maybe compared to other american politicians he is, but compared to russian opposition he is very like Boris Nemtsov and Alexey Navalny. First is literal founder of Union of Right Forces, second is considered to be center-right.
The simplest explanation is that the American “left” is rightwing, because they’ve been told that actual leftism is bad.
We’re only told about leftist ideology or politics in the context of “these bad people in the past did bad things”, and many Americans refuse to actually tackle those lies. because of this, no one in the American “left” is willing to be anti-capitalist in any way that actually matters. Nor are they willing to use materialism in their dialectics, because their political education comes from Liberalism, so they’re more willing to listen to right-wing talking points and integrate them into their views.
This is why you’ll see Americans who’ll call themselves “leftists” pair a statement for working rights with a statement against immigration. Or you’ll see them decry the horrors of fascism, then support whatever new war NATO has wrought.