On March 27, a Missouri Democrat filed a lawsuit against the Secretary of State, because she refused to let him appear on the Democratic primary ballot for U.S. House, 7th district. The Secretary of State refused to accept his candidacy because the Democratic Party of Missouri said the candidate, Glenn Miller, is a white supremacist (Miller accepts this designation as accurate). Miller v Missouri Secretary of State, 06-5032-cv-SW.
A few states empower political parties to reject a member or a candidate in that party’s own primary, if the member or candidate is not in sympathy with party principles. However, Missouri has no such law. Therefore, the state will need to establish that there is a common law right for political parties to exclude, something that will probably be difficult to do. This case may create an interesting precedent.