A perceptive student of the supply-side theology might wonder: if revenue from higher taxes will simply be spent, why wouldn’t revenue from higher growth also be spent? But this question has never been asked, because there are no perceptive students of the supply-side theology. It’s just a series of talking points.
In any case, it’s worth keeping in mind that the entire conservative apparatus is already cranked up to insist that no tax hikes are acceptable in the pursuit of deficit reduction. I see no way around this problem unless and until the country actually begins to undergo a deficit-created economic calamity.