Income in Illinois is taxed at a uniform five percent, whether you're working at a drive-thru window or you're the CEO of a multi-national corporation.
The people pushing what they call a "fair tax" would have wealthy people pay more, while middle- and lower- income people would pay less. That's already how federal income taxes work.
John Bauman, with the Shriver Center on poverty law, says the change would be good for businesses in Illinois. He pointed to state-funded education, road building, and health care.
"Businesses care a lot more about that stuff than they do about the marginal tax rates that their highest-paid executives are going to have to pay."
So far, 61 state lawmakers have signed on to the proposal -- all Democrats. Because it would involve changing the Illinois Constitution, it would require extra votes in order to pass.
Republican leaders say they're opposed to a graduated income tax. They say it'll just lead to more government spending.