This makes sense. Republicans campaigned on a giant middle-class tax cut, but they’re pushing a plan that delivers the lion’s share of its benefits to wealthy business owners and corporate shareholders. To reconcile this apparent contradiction between their rhetoric and their policy agenda, GOP lawmakers have insisted that the middle class actually has an enormous stake in boosting corporate profitability — even if many middle-income Americans have no literal stake in that matter. Reciting the trickle-down gospel, Republicans have argued that reducing the cost of capital will turbocharge investment; and thus, economic growth; and thus, middle-class wages. If supply-side economic theory is demonstrably false, then the GOP has no politically viable argument for its agenda.
So, naturally, progressives have been eager to note that supply-side economic theory is demonstrably false. The Bush tax cuts failed to produce the growth that supply-siders promised. Kansas implemented Paul Ryan’s blueprint for utopia — and ended up with four-day school weeks, weaker growth than its (higher tax) neighbors, and, eventually, a GOP-led legislature voting to ditch the “red-state model.” Supply-side experiments in Oklahoma and Louisiana replicated these results. But one doesn’t even need to turn to these precedents to know that businesses will not spend their tax cuts as Republican economists predict: America’s leading companies have been explicitly assuring their shareholders that the Trump tax cuts will not trickle down (or, rather, not trickle down below them).