He didn’t say they were _the_ corporate party, just that they’re dominated by corporations. It’s notable because it’s an accusation that they pitch at Republicans often (not that R is doing any better there, but it’s part of their platform more or less).
The dems haven’t done anything notably anti-corporate in ages. There are rumbles about doing it (anti trust, supporting unions, climate change), but it never _quite_ seems to actually materialize into anything.
Cynically, that’s why both sides lean so hard into the culture wars. The men in suits would rather we argue about how to interpret history than whether a wealth tax makes sense.