INCOME TAX RATES Senate SponsorsSen. Michael W. Frerichs-Kwame Raoul-David Koehler-Heather Steans-Jacqueline Y. Collins and Don Harmon 1/13/2009SenateSession Sine Die ILCON Art. IX, Sec. 3 Proposes to amend the Revenue Article of the Illinois Constitution. Authorizes a tax on or measured by income to be at a graduated rate (now, all taxes on or measured by income shall be at a non-graduated rate). Provides that, in any such tax imposed upon corporations, the rate shall not exceed the average rate imposed on individuals by more than a ratio of 8 to 5. Effective upon being declared adopted. 4/2/2008SenateFiled with Secretary 4/2/2008SenateAdded as Chief Co-Sponsor Sen. Kwame Raoul 4/2/2008SenateAdded as Chief Co-Sponsor Sen. David Koehler 4/2/2008SenateAdded as Chief Co-Sponsor Sen. Heather Steans 4/2/2008SenateReferred to Rules 4/2/2008SenateAdded as Chief Co-Sponsor Sen. Jacqueline Y. Collins 4/8/2008SenateAdded as Co-Sponsor Sen. Don Harmon 1/13/2009SenateSession Sine Die