A stubborn myth of the pro-tax left (exemplified by Bernie Sanders) is that the Reagan tax cuts merely benefitted the rich (aka Top 1%), so it would be both harmless and fair to roll back the top tax rates to 70% or 91%.
Nothing could be further from the truth. Between the cyclical peaks of 1979 and 2007, average individual income tax rates fell most dramatically for the bottom 80% of taxpayers, with the bottom 40 percent receiving more in refundable tax credits than paid in taxes. By 2008 (with the 2003 tax cuts in place), the OECD found the U.S. had the most progressive tax system among OECD countries while taxes in Sweden and France were among the least progressive.
What is commonly forgotten is that before two across-the-board tax rate reductions of 30% in 1964 and 23% in 1983, families with very modest incomes faced astonishingly high marginal tax rates on every increase in income from extra work or saving (there were no tax-favored saving plans for retirement or college).
From 1954 to 1963 there were 24 tax brackets and 19 of those brackets were higher than 35%. The lowest rate was 20% -double what it is now. The highest was 91%.
High and steeply progressive marginal tax rates were terrible for the economy but terrific for tax avoidance. Revenues from the individual income tax were only 7.5% from 1954 to 1963 when the highest tax rate was 91%, which compares poorly with revenues of 7.9% of GDP from 1988 to 1990 when the highest tax rate was 28%.