The Arizona Supreme Court Friday ordered the open primary initiative onto the November general election ballot.
In a brief order, the court said it was overturning a Maricopa County Superior Court judge's order that the initiative be disqualified.
That was based on a claim by Republican opponents of the measure that it violated the state Constitution's requirement that a proposed constitutional amendment deal with one issue.
The open primary would change the fundamental election system in the state to allow all candidates to run on a single ballot for a given office, and all voters to decide among them. The top two vote getters, regardless of party, would move on to the general election.
The proposal is being pushed by a group called the Open Government Committee, headed by former Phoenix mayor Paul Johnson.
Republicans and Democrats are opposed to it, saying it would allow for sham candidates running under false party affiliations to undermine the two-party system.