What he's doing can't even be considered Keynesian. Keynes was never about f'ing with the supply side. He new full well the supply side was needed. Especially in times when demand just wasn't cutting it.
It's no longer about competing economic theories.
They had to sell Keynes using the idea of "fairness" for the working guy. Promises of future fairness implies current states of unfairness. Promises of future remedy implies no current chance of self-remediation.
That, in turn, evolves into tales of a system too morally bankrupt to allow The Little Guy
TM a place at the table of opportunity.
Moral bankruptcy demands a villain.
Villains must be denied power if justice is to prevail.
But the power never disappears, as of it were a force subject to the thermodynamic law of conservation.
So the liberals must seize the power for themselves.
They must because they are the victims/heroes of the morality play.
Just look at the flip side: How many DUmbasses wail that life has been cruel and unfair and it is the fault of The Others. How many of them imagine themselves the noble champion of the downtrodden. They'll be happy to prove how much smarter they are, all you have to do is relinquish all power to them and they will show you.
It's all very Shakesperean in its pathos and tediously predictable in its trajectory.