In 2016, a Democratic candidate for Illinois State House sued Illinois House Speaker Michael Madigan, over Madigan’s action in recruiting two Hispanic-surnamed opponents to enter the race for the Democratic nomination for Madigan’s seat. The plaintiff, Jason Gonzales, was also running in the Democratic primary against Madigan. He presented evidence that incumbent Madigan had recruited the two other candidates in order to split the vote of people who wanted to vote for a Hispanic-surnamed candidate.

Under an old Seventh Circuit precedent, recruiting sham candidates in a primary to split the vote violates voting rights. Madigan won the current case in U.S. District Court in September 2019, but Gonzales then asked for reconsideration on September 20, 2019, and it is still pending. Judge Matthew Kennelly asked Madigan to respond to the rehearing request, and that response was received October 11, 2019.

Any candidate who hopes to be on the November 2020 ballot for Congress or state legislature (which are the only partisan offices on the 2020 ballot other than President) must file by December 6, 2019. This is because the California primary for all office is in March 2020, and the top-two system does not provide any method for a candidate to get on the November ballot except by placing first or second in the primary.

The December 6 deadline is extended a few days for offices in which the incumbent does not file for re-election.

Josh Mahony, the only Democrat who filed to run for U.S. Senate in Arkansas in 2020, withdrew, after the filing deadline had passed. See this story. If the Democratic Party is not permitted to replace him, the only candidates on the November ballot with be the Republican incumbent and the Libertarian nominee. UPDATE: there is also an independent candidate, Dan Whitfield, who expects to collect the needed 10,000 signatures by the May 1 petition deadline. The law does not permit him to start collecting until January 1, 2020, and then he has 90 days to get his signatures.