The Michigan U.S. House seat, 13th district, has been vacant all year, ever since John Conyers resigned in the middle of his term. Michigan election officials refused to call a special election early in 2018, saying it was cheaper to wait until the August 7 primary to let parties nominate for the remainder of the term, and then to let the November 2018 election fill that short term. At that point the term would be less than three months long.
Brenda Jones, a candidate for the short term seat, and also the full term 2019-2020, had the bad luck to win the Democratic primary for the short term, but to lose the primary for the 2019-2020 full term. She is now President of the Detroit City Council. According to this story, she is unlikely to want to give up her service on the city council, just so she can be a member of Congress for the short period November 2018-January 2019. But she can’t do much about it. Thanks to Thomas Jones for the link.