On May 1, 2019, the Illinois State Senate approved a constitutional amendment that would repeal the state’s constitutional requirement that the state personal income tax be a flat rate across income. Instead, the amendment would allow the state to enact legislation for a graduated income tax. Voters would address the constitutional amendment at the general election in 2020 if it is approved in the House.
In Illinois, a 60 percent vote is needed in each chamber of the Illinois General Assembly to refer a constitutional amendment to the ballot for voter consideration. In the state Senate, the amendment passed along partisan lines. Democrats supported the amendment, and Republicans opposed the amendment. Democrats have supermajorities in both legislative houses and can pass amendments without support from Republicans. In the state House, 71 votes will be needed to pass the amendment. Democrats control 74 seats in the state House, and Republicans control 44 seats.
Sen. Don Harmon (D-39), who voted for the amendment, stated, “If you’re saying the flat tax is a good idea, you are protecting the uber-rich, not the middle class. Because we can’t raise taxes on anyone without raising taxes on everyone, and that’s a protection for the richest among us.” Sen. Dale Righter (R-55), who voted against the amendment, said, “There are a handful who believe that the answer to government’s problems is simply to raise taxes. This will make it easier for those who believe that to reach into your constituents’ pockets and get more money.”
Gov. J.B. Pritzker (D) supports the constitutional amendment and campaigned on a graduated income tax during his gubernatorial campaign in 2018. Pritzker defeated incumbent Republican Gov. Bruce Rauner.
In addition to the constitutional amendment, the state Senate approved a bill changing the state’s income tax from a flat rate to graduated brackets beginning on January 1, 2021, if voters approve the constitutional amendment in 2020. For income earned in 2018, the personal income tax in Illinois was a flat rate of 4.95 percent. Under the bill, the income single filers who earned $750,000 or less would be marginal rates between 4.75 percent and 7.85 percent. The income of single filers who earned $750,001 or more would be 7.99 percent on their total net income.