In 2020, Illinois voters overwhelmingly voted down a signature initiative of Governor Pritzker that sought to enact a graduated income tax system in the State of Illinois. Senator Martwick proposed SB2105 this past week, the bill proposes installing a graduated income tax in Illinois.

While this legislation has been brought forward, it is important to note that this specific bill does not propose a constitutional ballot initiative. Instead it seeks to change the income tax system by statute, something that is expressly not authorized by the state constitution.

The Illinois Constitution clearly lays out that the state’s income tax system is non-graduated:

SECTION 3. LIMITATIONS ON INCOME TAXATION
(a) A tax on or measured by income shall be at a
non-graduated rate. At any one time there may be no more than
one such tax imposed by the State for State purposes on
individuals and one such tax so imposed on corporations. In
any such tax imposed upon corporations the rate shall not
exceed the rate imposed on individuals by more than a ratio
of 8 to 5.

Ill. Const. art. IX, sec. III.

This language shows why it was necessary to try to have this change passed by referendum, rather than by statute.

Senator Martwick’s SB2105 proposed a top rate of 6.95%, which is over a 40% hike from the current income tax rate and over an 85% increase from what the rate was until 2017. The 2017 increase raised the individual flat rate from 3.75% to 4.95%, a supermajority of the General Assembly voted to override Governor Rauner’s veto of the proposal.

CONCLUSION

While it seems that this bill would not pass constitutional muster, this proposal shows that the talk is unlikely to go away anytime soon. There is a good chance that a referendum will end up on the ballots of voters again soon. While an effort from Republican Senate Leader John Curran would block the ability to ask voters again, that measure is unlikely to go anywhere with Democratic super majorities in both chambers.

Jake Leahy

Jake A. Leahy

Attorney

Jake A. Leahy is a tax attorney at Airdo Werwas who counsels nonprofits, local governments, and businesses in tax, regulatory, and commercial matters.

He is a former Assistant Illinois Attorney General in the Revenue Litigation Bureau, where he handled…

Jake A. Leahy

Attorney

Jake A. Leahy is a tax attorney at Airdo Werwas who counsels nonprofits, local governments, and businesses in tax, regulatory, and commercial matters.

He is a former Assistant Illinois Attorney General in the Revenue Litigation Bureau, where he handled estate tax litigation, collections audits, and matters involving various state agencies. He previously served as a Judicial Law Clerk in the Circuit Court of Cook County, Law Division, Tax & Miscellaneous Remedies Section, working on administrative review actions, commercial disputes, and tax-related litigation.

Jake previously served on the Board of Education for Bannockburn School District 106 from 2017 to 2023, including as Vice President from 2020 to 2023. His experience in local government informs his work with public-sector clients, boards, and nonprofit organizations.

Jake is active in professional and bar organizations. He serves as an Assembly Member of the Illinois State Bar Association, Chair of the Chicago Bar Association’s State & Local Tax Committee and Young Lawyers Section Federal Tax Committee, and a member of the Editorial Board of the DuPage County Bar Association. He was recognized by the Illinois State Bar Association with its Law Student Public Service Award during law school, and by the Internal Revenue Service for his work with the Low-Income Tax Clinic at Holy Name Cathedral.

Jake earned his LL.M. in Taxation from Georgetown University Law Center, his J.D. from the University of Illinois Chicago School of Law, and his B.A. from the University of Illinois at Urbana-Champaign. He is admitted to practice in Illinois, the U.S. Tax Court, and the U.S. District Court for the Northern District of Illinois.

Outside of practice, Jake has completed three marathons, is a regular at Wrigley Field, and appreciates Chicago architecture.

Education

    • Georgetown University Law Center, LL.M. in Taxation, 2025

    • University of Illinois Chicago School of Law, J.D., 2023

    • University of Illinois at Urbana-Champaign, B.A. Political Science: Public Policy & Democratic Institutions, 2019

Admitted to Practice

    • Northern District of Illinois, 2025

    • U.S. Tax Court, 2024

    • Illinois, 2023

Associations

    • Illinois State Bar Association

    • Chicago Bar Association

    • American Bar Association, Tax Section

    • DuPage County Bar Association

    • Celtic Law Association