There's no doubt some of his depression era policies were socialist. He characterized them as pragmatic - correctly so I believe.
The Great Depression began in '29 and reached its peak in '33. Nothing the Republicans did under Hoover worked - making all discussion of what happened under Harding in '20 irrelevant.
The raison d'etre of democratic capitalism is that it delivers prosperity. When it doesn't, when it delivers misery and failure and its principal exponents can do nothing about it, then people question its worth. That's what was happening. When the troops fired on Hooverville you knew drastic measures were needed.