By The Associated Press
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The justices said they will not hear appeals from the state Democratic and Libertarian parties opposing a system that allows primary candidates to identify themselves as members of a party even when the party objects.
The parties said the system could confuse voters.
But the San Francisco-based 9th U.S. Circuit Court of Appeals said there is no evidence of confusion and upheld the system.
Under the top-two system, the top two finishers in a primary advance to the general election, even if they’re both Democrats or both Republicans.
The Supreme Court upheld the system in 2008 but acknowledged there could be additional challenges.