Arthur Jones, a white supremacist, is the only person who filed petitions to be on the Republican primary ballot for the U.S. House, 3rd district. He needed 603 valid signatures. No one challenged his petition, so he is on the ballot and no one is running against him for the Republican nomination.
Five individuals did examine his petition, according to the Illinois State Board of Elections’ web page, so even during the challenge period, there was an awareness of Jones’ filing. See this story.