Have a look at the interactive graphic on total tax rates at this link. Scroll up and down to make the graph show data from different decades.
Opinion | The Rich Really Do Pay Lower Taxes Than You (Published 2019)
The 400 wealthiest Americans now pay a lower rate than the middle class.www.nytimes.com
Rates have fallen.
Portion of income taxes paid by the rich has increased, portion paid by the middle class and lower classes has fallen.
And Buffett is full of shit.
And the claim that the 400 richest pay a lower rate is also false.
How about a link or two there Todd? And perhaps an explanation on why you think the fairness of a taxation scheme is dependent on the total revenue from a class? I think it would be more fair for the wealthy to pay a higher total rate than the poor. That is NOT the current situation thanks primarily to good old Mr Trump and the RNC.