On April 11, a state trial court in Iowa removed Abby Finkenauer from the June 7 Iowa Democratic Party primary ballot, because she was three signatures short. However, she had enough signatures statewide, and the state law that requires a certain number of signatures for a certain number of counties is unconstitutional under Moore v Ogilvie, a 1969 U.S. Supreme Court that invalidated county distribution requirements for statewide petitions. There are about a dozen similar precedents from lower courts. The two most recent are Constitution Party of Pennsylvania v Cortes, 877 F.3d 480 (2017) and Montana Green Party v Jacobson, 17 F.4th 919 (2021). See this story. The case is Schmett v State Objections Panel, Polk Co., cv63390. Thanks to Thomas Jones for the news.
Finkenauer is considered the most likely candidate to win the primary, assuming she eventually gets on the ballot. She is appealing. The Iowa distribution requirement is 100 signatures from each of nineteen counties.