Quick reminder that "liberalism" in the United States is centrism in every other developed nation.
Bernie & co. are left of center.
Most Dems are slightly right of center, with Pelosi, Hillary, and most establishment Dems being further right.
Not as much as you think. Your mistake is assuming that because we are ok with compromise that it's the option we're all ok with, when it's more complicated than that. Don't confuse strategy with ideology. Many of us would love for more left leaning bills, but we realise that believing so does not make it an easier to get the bills pass congress.
Not in America, they're not. Leftists don't own every inch of the left political spectrum in the US, thus we're using US centric spectrum. Being slightly more conservative to you is not right wing.
Global comparisons are useful, but with this? It's useless because you're not talking about France or the UK.
The only reason our overton window is so fucked is because a) Republicans exist and b) our nation is one built on supporting the status quo.
You're missing a crucial factor in this equation - the system itself. Something which can't be gone around or obliterated, or the left would have done so decades ago. So we're stuck working within the system and adjusting it to our advantage. It's messy and horrible but without it we have nothing.
First off, it's the Intercept. Second, any congress leader worth their salt will be trying to get all the parties necessary on board within their coalition. Which, for now, involves, insurance companies.
This context ignores how Pelosi is more left than you're painting her.
She's for Single Payer and the Public Option, for example.