In the event that the Governor, for any of the reasons specified in the constitution, is not able to exercise the powers and discharge the duties of his office, the officer next in line of succession as provided in Section 1 of "An Act in relation to succession to the office of Governor", enacted by the 82nd General Assembly, shall succeed to the office of Governor.
5 ILCS 275/4
Additional successors to Office of Governor
Known as the Emergency Interim Executive Succession Act
The act spans §§ 5-275-1 to 5-275-9 (11 sections).
P.A. 82-105.
Official source: Illinois General Assembly. Reproduced from public-domain Illinois statutes; confirm against the official source for the current text. Not legal advice.