In what is shaping up to be one of the most expensive state Supreme Court races in Washington history, two judges with lengthy résumés are locked in a hotly contested campaign for the judiciary.

This year will be particularly consequential for the high court, with five of nine seats on the ballot after a suite of departures. And while judicial races are nonpartisan in the state, political interests — and the money that comes with them — are playing a role.

The tension has come to a head in the race for Position 4, where the candidates have raised just over $1 million combined. King County Superior Court Judge Sean O'Donnell has accused his opponent of bringing politics into the race, a charge that Court of Appeals Judge Ian Birk described as a superficial double standard. The tiff garnered unusual attention for what are, typically, sleepy and nonpartisan campaigns.

Even as the candidates trade barbs, University of Washington retired law professor Hugh Spitzer had a more relaxed take: "Whoever wins is not going to change the fundamentals of the court. They're both moderates. They are both experienced … and they are both respected."

"They're just not that different," he said.

Birk, 48, whose campaign has garnered about $578,000, has served on the Washington State Court of Appeals since 2022. Before that, he spent two decades in private practice, filing lawsuits over insurance claims and workplace discrimination. He also clerked for the Washington Supreme Court earlier in his career and received his law degree from the University of Washington.

O’Donnell, 54, whose campaign has raised about $499,000, has been a King County Superior Court judge since 2013. He has served as a pro tem justice — a substitute judge — for the Supreme Court on select cases. Before, he was a senior deputy prosecutor, where he handled trafficking cases. He was also a member of the Green River Task Force, which oversaw the investigation and prosecution of serial killer Gary L. Ridgway. He received his law degree from Seattle University.

Birk boasts endorsements from state leaders, such as Gov. Bob Ferguson and Attorney General Nick Brown, as well as numerous local unions.

O'Donnell is endorsed by U.S. Rep. Adam Smith, former Gov. Christine Gregoire and several law enforcement unions.

Despite their differences, both candidates vowed to protect Washingtonians' constitutional rights and look at the consequences of potential decisions alongside the constitutional text.

"I will respect the Constitution and the letter of the law, but I also give grace to people and what they've been through and why they're in front of me," O'Donnell said.

Birk touted his experience in appellate law as experience in serving on "a court of policy" — making decisions that shape the common law going forward. He said he was urged by colleagues at the Court of Appeals to run.

"Our state law, our state rights, the Washington Constitution and the Supreme Court that interprets the Washington Constitution have never been more important than they are now — at least not in my lifetime," Birk said.

Increasingly, as the U.S. Supreme Court has handed pivotal legal questions back down to the states, state supreme court races have turned fiery and increasingly expensive. Washington's races have not seen the tens of millions of dollars in political funding from outside the state that Wisconsin experienced last year, but the races have become more contentious, a trend embodied by Birk and O'Donnell's political tussle last month.

In campaign emails, Birk sent messages to voters saying O'Donnell was running with a “partisan agenda” that is “out of touch with the values and priorities" of voters. O'Donnell was recommended by the Washington GOP but said he did not seek out an endorsement (and the party is not listed among the endorsements on his campaign website).

O'Donnell solicited signatures from 62 judges statewide on a letter that rebuked Birk for making "partisan attacks."

Birk, in an interview, argued that O'Donnell has been "doing the very same thing," including going after Birk for his history of making more extensive political contributions to progressive politicians.

Birk said he didn't regret the statements from his campaign and saw it as "pretty ordinary campaigning," adding that it was fair for O'Donnell to mention his past donations. However, he argued those donations don't reflect an inability to be impartial on the court.

"When you become a judge, you hang up your partisan ties and affiliations," Birk said.

O'Donnell said he has a "record of impartiality" and deep experience on public safety that is unmatched by other candidates in the judicial field this year. He boasts more support from both sides of the political aisle, and he said that it's "unfathomable" that he would be asked in a nonpartisan race to disavow a major political party.

"Do you want an impartial judiciary, or do you want candidates who will bend the knee to a certain party the fastest?" he said.

The code of judicial conduct mandates that candidates do not indicate how they would rule on a particular issue if there's a chance it would come before their court.

Birk and O'Donnell offered their thoughts on what the high court might have to consider in the coming years.

Both said they expected the crisis in hiring criminal attorneys to be an issue. They also speculated that the court would look at cases involving housing, affordability of civil legal aid and artificial intelligence.

The candidates declined to speak at length on the "millionaires tax" that is likely to come before the court, as voters are poised to weigh in on Initiative 645, which would repeal the new income tax.

"We will get cases in which deciding it one way or the other will force us to be unpopular, and our job is to be neutral with respect to the constitutional principle and apply that without a political agenda," Birk said.

Spitzer, the retired law professor, said he "cannot predict" how either would rule if the income tax comes before the court.

He predicts the court's overall makeup likely won't change much. What makes this year unique, he said, is how much turnover will take place.

With two "good, solid judges" on the ballot — and a race where there wasn't a primary — it's difficult to assess who may land on top, Spitzer said. Looking at the state's history, he said, it's not infrequent that in a close election between two qualified judges, the loser makes a successful bid for Supreme Court justice a couple of years later.

"I think the court is just going to continue to be this sort of centrist to somewhat progressive court, whatever happens," Spitzer said.