Statewide Delegates: Proportional - the candidates are awarded delegates in proportion to the percentage of votes received. - a 15% threshold is required to receive delegates. Congressional District Delegates: Proportional - the candidates are awarded delegates in proportion to the percentage of votes received. - a 15% threshold is required to receive delegates.
Source for Popular Vote data: Illinois State Board of Elections. 2016 General Primary Official Vote Totals Book - President of the United States (pp. 1-13), Illinois State Board of Elections (http://www.elections.il.gov/Downloads/ElectionInformation/VoteTotals/2016GPOfficialVote.pdf) (accessed 16 Apr 2016)