From 2008 to 2016 all the growth in the American economy, all the growth in national income, was earned just by the wealthiest 5% of the population. So they got all the growth. 95% of the population didn't grow. If you can get a flat tax or other lower tax, as Trump is suggesting, then this richest 5% will be able to keep even more money. That means that the 95% will be even poorer than they were before, relative to the very top.