You need to distinguish between the scientific proposition that Say's law doesn't automatically hold and therefore aggregate demand can be propped up by monetary or fiscal instrument with the more tortured question of how best to do this and whether government can deliver what would be technically ideal. The former question has been answered, and truthful macroeconomists will tell you Hayek was wrong and Keynes right, even if they prefer Hayek's politics. The latter question is more a matter of practical judgment than economic science. Naturally, ideology becomes a bigger predictor than expertise at that point.

I'm quite sure that if you polled the top 100 macro economists there would be overwhelming support for stimulus.

Credibility here is sinking *way* fast.

“These concerns are not a sufficient reason for rejecting the stimulus plan, but rather a call to consider its implications for long-run growth. Decisive action on the crisis is necessary; not just soften the blow of the recession but also to avoid a backlash that could be deeply harmful to long-run growth…

…A comprehensive stimulus plan, even with all of its imperfections, is probably the best way of fighting these dangers. Nevertheless, the details of the stimulus plan should be designed so as to cause minimal disruption to the process of reallocation and innovation.”

It's possible, of course that he's he's written something critical of the details elsewhere.