How much evidence that something doesn’t work must one accumulate to conclude it’s time to try something different? If I have an irritant in my eye, and I choose to try to dislodge the offending particle by repeatedly whapping myself in the face with a ball-peen hammer, how many whaps shall I allow my face to withstand before, say, splashing some water on the little bugger instead? How many whaps does it take to convince one the method has failed? Apparently, with regard to supply-side “trickle down” economics, 40 years of whaps doesn’t quite cut it. This next whap, surely, will do the trick.