I will say that there's a big myth that the US has been on some big market-oriented supply-side binge since the 1980s which is a giant myth in itself. The size of western governments, everywhere, has exploded since the 1970s... even if the tax rate hasn't.
Sowell would be just as critical of any policy directly benefiting the wealthy as well. He sees the far bigger problem as the countless "well-intentioned policies" intended (or at least sold) to help the poor/middle class that back fire, do nothing, or more often creates highly inefficient systems where only the politically connected get social benefits.
I highly recommend his book "Wealth, poverty, and politics" . It'd do a 100x better job than me at explaining his general worldview, which is closest to mine. And it's hardly just lower taxes for upper/middle and keep the rest of the political machine the same (which is probably worst of both worlds IMO).