Illinois held state legislative primaries on March 17, 2020. There were 38 contested party primaries: eight for state Senate seats and 30 for state House seats. Twenty-eight were Democratic primaries and 10 were Republican primaries.
Two Democratic incumbents lost primary bids: Rep. Yehiel Kalish, House District 16, and Rep. Yoni Pizer, House District 12.
This was the first election for both incumbents. Kalish was appointed to his position in 2019 following the resignation of Rep. Lou Lang (D). Pizer was appointed in 2020 following the appointment of Sara Feigenholtz (D) to the state Senate.
The primary in House District 3 remains too close to call. Incumbent Rep. Eva Delgado (D) leads Nidia Carranza (D) by a margin of 362 votes. Delgado was appointed to her position in 2019 following the arrest and resignation of Rep. Luis Arroyo (D).
The 38 contested primaries this year was fewer than the 61 contested primaries in 2018, but greater than the 33 in 2016.
In the House, a decade-high 92 percent of races (109) featured an incumbent. In the Senate, a decade-low 70 percent of races (14) featured an incumbent. Incumbents ran in 22 of the 38 primaries.
Of the 20 seats up in the Senate, 14 will have an incumbent running in the general election. Of the 118 seats up in the House, at least 106 will feature an incumbent.
Democrats hold a 40-19 supermajority in the Senate and a 74-44 supermajority in the House. Illinois became one of 15 Democratic state government trifectas when Gov. J.B. Pritzker (D) was elected in 2018.
The Illinois General Assembly will be responsible for drawing both state and congressional district lines after the 2020 census.