The Michigan Tea Party (the ballot-qualified party), which most observers feel is an insincere party artificially created by Democrats, recently nominated 23 candidates. But two of them will not appear on the ballot because they are under age 21. The Michigan Constitution requires legislators to be age 21 or older. See this story.
One of the candidates who is being removed from the ballot was running in the 13th State Senate district. This is one of the most closely-balanced State Senate districts in Michigan. Last time voters chose a State Senator in this district, in 2006, the vote for the two major parties had been: Republican 57,204; Democratic 56,484. Thanks to Thomas Jones for the link.