Politifact rated this as TRUE. Here is why:
Due to Bush tax cuts after-tax incomes for the top 1 percent of taxpayers increased by 5.4 to 6.7 percent. The same group would see incomes gains of 10.2 to 19.9 percent under the Trump tax plan, and perhaps even more.
Under Bush, the top 1 percent received a tax break equivalent to 0.66 percent of GDP. With Trump’s tax plan they would deliver a cut equivalent to 1.32 percent of GDP.