> If the supermajority of progressives SF can't create a progressive city, then it simply isn't possible

Or, one of

a) They're not really, deep down, as progressive as they claim to be.

b) it's not possible, _within the USA as it currently operates_.

c) Related to b, power to "create a progressive city" doesn't actually lie with the "supermajority" of voters, but with a few powerful people who are fine with things the way they are.

I suspect, with no evidence, a bit of all of these.