An “open primary” is defined as a primary in which the voter is free, on primary election day, to choose any party’s primary ballot. There are two kinds of “open primary”: one in which the primary voter must publicly ask for one of the party ballots, and one in which the voter can choose a primary ballot in secret. On March 10, the Illinois Senate Elections Committee passed SB 1666, to switch Illinois from a state in which the voter must publicly choose a primary ballot, to a state in which the voter decides which primary ballot to use in the secrecy of the voting booth.

The sponsor of SB 1666 is Senator Larry Bomke (R-Springfield). His bill passed on a 5-4 vote. All four Republicans on the Committee, plus Democratic Senator Maggie Crotty, voted for the bill.