Looking at the federal income tax rate is only a small part of the picture. There are a lot of other taxes everyone pays, payroll taxes / fica, sales taxes, etc

Looking at the federal income tax rate is only a small part of the picture. There are a lot of other taxes everyone pays, payroll taxes / fica, sales taxes, etc.; most of which are highly regressive. You could cut those for lower income brackets. When you include these tax categories you will also note that there was a shift to these regressive taxes at the same time the highest income tax rates were cut. And to further reinforce this feedback loop there was also a move to reclassify income to long term capital gains profit which is taxed even lower than the highest income tax. All of these policy shifts combined to create greater wealth inequality, and wage stagnation.