Tucson’s unusual method of electing council members will remain.

The U.S. Supreme Court on Monday morning rebuffed a bid by a group representing some Republicans to void the system of nominating council members by ward and instead have them elected at large. The justices gave no reason for their ruling.

Monday’s action is the last word in the multi-year bid by the Public Integrity Alliance to have state and federal courts declare that the practice is an unconstitutional violation of the Equal Protection Clause of the U.S. Constitution. Attorney Kory Langhofer, who represented challengers, argued that the system gave some voters more power than others and, in some cases, effectively nullified their votes.

But that contention was most recently rejected by the 9th U.S. Circuit Court of Appeals.

“Tucson’s hybrid system for electing members of its city council imposes no constitutionally significant burden on voters’ rights to vote,” the appellate court concluded. “And Tucson has advanced a valid, sufficiently important interest to justify its choice of electoral system.”

Langhofer told Capitol Media Services the loss is not entirely unexpected.

“I think that what happens when you sue the government… there’s a thumb on the scale for the government in litigation,” he said.

“In some cases, it’s not even invisible,” Langhofer continued, saying that courts generally start with the premise that a law is constitutional. “We’re sort of bumping up against that in this case.”

And there was something else. Langhofer said federal courts are reticent to impose federal rules on state and local election laws.

But it’s not just federal courts. In a 2012 ruling, the Arizona Supreme Court threw out a state law which also sought to invalidate Tucson’s election system.

At the heart of the latest challenge is the question of some voters nullifying the rights of others.

In the city’s six wards, Republicans hold a voter registration edge in one. But all six council members are Democrats.

That reflects the fact that the winners in each ward of each party’s political primary then have to run on a city-wide basis. And with more Democrats in Tucson than Republicans, that means the voters in the other five wards can choose the Democrat to represent the sixth, even though more voters in that ward voted for the Republican.

Langhofer argued that system gives the city “a nearly unfettered ability to deny the right to vote in the primary election.”

The full appellate court did not see it that way.

“Ultimately, every voter has an equal opportunity to vote in their own ward’s primary every four years and in the general election every two years,” Judge Marsha Berzon wrote for the court last year.

“As is constitutionally required, then, every voter in Tucson has the same voting power as every other voter in the primary and general city council elections,” she wrote. “There is no unequal weighting of votes, no discrimination among voters, and no obstruction or impediment to voting.”

Had Langhofer won the case, it would have changed the Tucson election system for the benefit of Republicans. If council members had to be elected by ward at the general election, that could have given Republicans a better chance of getting one or more members on the city’s governing body.

But Langhofer said the Public Integrity Alliance did not pursue the case for partisan reasons.

He said the group has been involved in other election issues, including intra-party topics like when it paid for commercials during the Republican primary attacking incumbent Attorney General Tom Horne. That helped Mark Brnovich win the primary, and he ultimately went on to defeat Democrat Felecia Rotellini.

This isn’t the first time Republican interests have sought to overturn Tucson’s voting system.

In 2009, Sen. Jonathan Paton, at the time a Republican state senator from Tucson, pushed through legislation which would have voided Tucson’s modified ward election system.

It also would have barred cities from conducting local elections where the candidates’ political affiliations are listed on the ballot. Tucson is the only city with such partisan elections.

That measure was overturned by the Arizona Supreme Court in 2012. The justices said Tucson, as a charter city, has a right under the Arizona Constitution to decide whether to conduct partisan elections and how to elect council members.