I see what you mean, but I'd disagree with the idea that there's “precisely zero ideological, ie political-economic, difference”.

That's true that since at least Clinton, the Democrats as a political party have mostly embraced the business-friendly view that is also the conservatives' position on the subject.

But the Democrat's leadership are only a (very) imperfect mirror of their electorate and of the intellectual left, and there is definitely a significant set of left-wing economists (Polanyi, Stiglitz, Piketti to name a few of the most prominent, in chronological order).