Appreciate the Pew link! I'd note thought that it talks about the general election, not primaries.
If the progressives don't outnumber the moderates and centrists even within the Democratic party, then that seems a pretty good indication that American politics is roughly in line with American attitudes, which would mean democracy is working as it should.
Here's the thing, Sanders got 43% of the primary vote iirc and Clinton got 55. This happened, despite the middle age and elderly voters showing up in significantly larger numbers than the young, presumably progressive ones. If the young voters had shown up and their vote patterns held, Sanders would likely have had a comfortable win.
I ow a how much?