The income tax rate was 90% on income over $400,000, post World War II. 
Reagan administration lowered it to 50%. 
In 1986 Republicans and Democrats lowered that rate to 28%. 
A teacher, factory worker, and billionaire would all pay the same 28%. 
The idea of a progressive income tax in which the rich pay the higher rate is now almost dead. As a result of the tax changes from 1978 to 1990, the net worth of the richest in the country tripled. 
(Howard Zinn, "People's History of the United States")

And this is government of, for and by, THE PEOPLE? Stop being screwed by the rich and stand up for your children, the weak, the earth, truth and justice. Time for economic justice! End welfare for the oil companies! Tax based on Robin Brenna's analysis. All Askans should pay but PROGRESSIVELY.