After LaRouche movement disciples won the Democratic primaries for Lieutenant Governor and Secretary of State, Adlai Stevenson III created the Solidarity Party primarily to run Democratic candidates against them in the general election.

The two Lyndon LaRouche-affiliated candidates, Mark J. Fairchild for Lieutenant Governor and Janice Hart for Secretary of State, had not seen their affiliations with LaRouche well-publicized until after they won their upset primary defeats over Stevenson-backed candidates George Sangmeister and Aurelia Pucinski.

[2] Illinois law required any unestablished party to run a full slate in order to obtain ballot access,[3] thus, Stevenson ran candidates in all races.

Incumbent Neil Hartigan defeated Chicago alderman Martin J. Oberman in the Democratic primary.

[7][8] There had been originally been several other candidates running for the Republican nomination in the primary, but all withdrew soon after Democratic incumbent Hartigan announced that he would seek reelection.

Little known candidate Janice Hart won an upset victory over Aurelia Pucinski (who had the backing of Adlai Stevenson III and others).

State Senator Adeline Jay Geo-Karis won the Republican primary unopposed.

[10][11] Other candidates running included Cook County Board of Appeals member Pat Quinn and LaRouche movement member Robert D. Hart (who had the formal backing of Lyndon LaRouche's NDPC).

An election was held for three of nine seats for Trustees of University of Illinois system for six year terms.

[4][13] First-term incumbent Republicans Galey Day and Dean E. Madden lost reelection.

[4] Illinois voters voted on two ballot measures in 1986,[14] both of them legislatively referred constitutional amendments.