According to Illinois Senate rules, any nomination that the Senate evaluates must be submitted to the Senate by an Appointment Message from the legally-designated appointing authority for the position in question. The Appointment Message is then by default controlled by the Chairperson of the Executive Appointments Committee as the primary and exclusive sponsor, and then it is assigned to the Executives Appointments Committee.
At any time, the appointing officer or appointing authority can withdraw an appointment in writing, terminating the legal effect of the initial Appointment Message. This is what happened to Hemme on March 25 when the appointee's nomination was withdrawn.
Sen. Antonio Muñoz (D-1) had been sponsoring Hemme's nomination.
Hemme had been nominated to be a member of the Illinois State Board of Investment during the previous General Assembly, and the appointment message carried over to the current General Assembly on Jan. 9.