Over the last half-century, the richest Americans have shifted the burden of the federal individual income tax off themselves and onto everybody else. The three convenient and accurate Wikipedia graphs below show the details. The first graph compares the official tax rates paid by the top and bottom income earners. Note especially that from the end of the Second World War into the early 1960s, the highest income earners paid a tax rate over 90 percent for many years. Today, the top earners pay a rate of only 35 percent. Note, also, how the gap between the rates paid by the richest and the poorest has narrowed. If we take into account the many loopholes the rich can and do use far more than the poor, the gap narrows even more.
One conclusion is clear and obvious: the richest Americans have dramatically lowered their income tax burden since 1945, both absolutely and relative to the tax burdens of the middle income groups and the poor.