I think it's more that, when people sit down and debunk the arguments against high tax rates, the people who believe in supply side economics don't read them. Which in some cases is because they'd rather watch old cowboy movies. In others, it's because they simply don't care. It's an extreme case - but consider what happened to the last accademic economist who tried to use economic arguments against the external imposition of supply side. He was called Yanis Varofakis. They ignored him, the press called him a nut, then they just went ahead with the austerity package.
