Bad ideas with different roots.
The Jeb! tax plan confirms if anyone had doubts that the takeover of the Republican Party by charlatans and cranks is complete. This is what the supposedly thoughtful wonkish candidate of the establishment can come up with?
And notice that the ludicrous claim that most of the revenue effects of huge tax cuts would be offset by higher growth comes from economists who like Jeb! are very much establishment figures – but who evidently find that the partisan requirement that they support voodoo outweighs any fear of damage to their professional reputations.
While the intellectual implosion of the GOP is obvious however it’s less obvious what is driving it. Or to be more specific stories that explain why one set of crank ideas flourish don’t seem to work well for other sets of crank ideas.
At least for now I don’t feel that I have a general theory of crankification. Instead I have two basic stories which seem to apply with very different force to different crank ideas.
Consider in particular the contrast between supply-side economics and Ron-Paul-style monetary crankdom.