Illinois constitution
Article V
Section 5

The election returns for executive offices shall be
sealed and transmitted to the Secretary of State, or other
person or body provided by law, who shall examine and
consolidate the returns. The person having the highest number
of votes for an office shall be declared elected. If two or
more persons have an equal and the highest number of votes
for an office, they shall draw lots to determine which of
them shall be declared elected. Election contests shall be
decided by the courts in a manner provided by law.