I've never encountered a radical centrist in the wild before. Now I can say I have. Fascinating.

But the politics of the Dems are absolutely pro-capital, pro-moderate, pro-"nothing fundamentally changes". Biden, Obama, Harris, and Clinton were all "let's not make any radical shifts here, the markets will sort us out, we just need some easily ignorable guard rails on them" candidates.

I don't think the party, at the national level, contains many leftists. Perhaps Sanders (though I think of him as a soc-dem, not a dem-soc, based on his policy positions), and he's not even a member of the party anymore.