The Michigan democrats are trying repeat their success in the 2022 mid-terms by removing the top Republicans from the ballot. Apparently, most candidates use a 3rd party to gather signatures, but those 3rd parties often have Democrats doing the work - and they enter invalid signatures. The D party knows this and later challenges the signatures and, behold, the Republican cannot be on the ballot.

2022: https://www.freep.com/story/news/politics/elections/2022/05/26/michigan-board-state-canvassers-petition-fraud-republican-governor/9939185002/

2024:

https://www.usatoday.com/story/news/politics/elections/2024/05/19/democrats-signatures-submitted-gop-senate-candidates/73759994007/