Illinois will keep its flat income tax, despite an effort to move to a graduated one.
Based on the General Assembly's schedule, the Senate would have had to pass the proposal Tuesday in order to meet a constitutional deadline.
Instead, senators adjourned without a vote.
The measure's sponsor, Senator Don Harmon, D-Oak Park, sticks by the plan.
He says would allow Illinois to be nimble with tax policy.
"This is the best way to finance government in a way that's fair to taxpayers, provides the revenue that we need to provide critical services, but does so in a way that is fair to minimum wage workers, middle class families and multi-millionaires," Harmon says.
Under a graduated tax, rates increase as incomes rise. Going that route in Illinois would require changing the state Constitution.
While Harmon was unable to get enough support to put it on the ballot this year, he says he'll work to get it done for the 2016 elections.
Conservatives, who claim a progressive tax would lead to higher rates, are celebrating the measure's defeat.