Pure supply-side economics is as documented and thorough a failure as pure communism.  Almost no reputable modern economist will even discuss it seriously.  Only the sad old guys like Laffer who sold that bag of s**t under Reagan still believe, and that's mostly because their reputation and legacy is chained to it.  Look what it's done at the state level to Southern states like Kansas who adopted it wholeheartedly.  You'll notice that the people selling it for Trump AREN'T economists..... they're bankers.  Bankers who stand to gain as much from it as Trump himself.