In December 2017, just days before President Donald Trump signed the $1.9 trillion tax legislation that would create sweeping changes to the U.S. federal tax system, he told television viewers that “it’s going to be one of the great Christmas gifts to middle-income people.”

For several months, the president had been selling the legislation on the claim that the tax cuts would “be rocket fuel for our economy.” His claim was critical to defending against the criticism that most of the tax cuts would go to corporations and the very wealthy—supposedly, the money would ‘trickle down’ to the middle class. Unfortunately, nearly two years of evidence show that his administration's estimates were wildly wrong.