The tax rates people quote are not usually effective rates; they're marginal rates, and no one really paid them.
The Reagan tax cuts were revenue neutral - they cut the top marginal rates and removed loopholes. During one of them the effective rate on the rich increased slightly.
>When you look back at the last few decades you will see that republicans have decided that rich people should pay an ever decreasing share.
The middle class and poor have seen very big tax cuts. For example, here [1] are effective tax rates from the CBO for years 1979-2005.
The lower quintile went from 8% to 4.3%, effectively halving their tax rate. 2nd quintile 14.3 to 9.9%, 3rd 18.6 to 14.2, third 21.2 to 17.4, highest quintile 27.5 to 25.5.
The top 1% went from 37% to 31.2%.
So, you claim rich do not pay their share? What is their "share"? The lowest 20% pays 4.4%, the top 1% pays 31.2%.
[1] https://www.cbo.gov/sites/default/files/cbofiles/attachments...