240 ILCS 10/21
If any provision, section, sub-section, sub-division, sentence, clause, or phrase of this Act shall for any reason be adjudged or declared by any court of competent jurisdiction to be unconstitutional or invalid, such judgment or decision shall not affect the validity of the remaining portions of this Act, but shall be confined in its operation to the provision, section, sub-section, sub-division, sentence, clause or phrase which shall have been adjudged or declared to be unconstitutional or invalid in such judgment or decision; and it is hereby expressly declared that every other provision, section, sub-section, sub-division, sentence, clause or phrase hereof would have been enacted irrespective of the enactment or validity of the portion thereof declared or adjudged to be unconstitutional or invalid.
240 ILCS 10/21