I remember reading in the Kahneman’s latest book, “Thinking Fast and Slow,” that a (very generous!) correlation between the quality of a CEO and a firm’s success is no more than 0.3. IOW, not much. I don’t think the influence of a president would be much bigger. Why should it?
I imagine a president (or a CEO) in a way goes with the flow and whatever that flow is, depends on a zillion of factors. But I understand we need scapegoats and heroes, FOX and MSNBC want to keep making money, and people in general need to keep acting like a bunch of apes that we are, pounding on our chest and cheering (or not) for the alpha male.