The court found that the senators are banned from running for reelection under a constitutional amendment approved in 2022.

The amendment, Ballot Measure 113, states that lawmakers who miss at least 10 legislative days without an excuse cannot seek reelection.

The ruling upheld a decision from Oregon Secretary of State LaVonne Griffin-Valade, a Democrat.

Ms. Griffin-Valade said in 2023 that the senators, under the measure, could not try for another term after their current term.

"My decision honors the voters' intent by enforcing the measure the way it was commonly understood when Oregonians added it to our state constitution," she said at the time.

The decision sparked a lawsuit from some of the Republican senators, but the Oregon Supreme Court sided with the secretary of state.

"Because the text is capable of supporting the secretary's interpretation, and considering the clear import of the ballot title and explanatory statement in this case, we agree with the secretary that voters would have understood the amendment to mean that a legislator with 10 or more unexcused absences during a legislative session would be disqualified from holding legislative office during the immediate next term, rather than the term after that," the new ruling reads.

Justices said they used their typical methodology in construing the amendment "by determining how the voters who adopted the amendment most likely understood its text." The method included considering the information presented to voters, which stated that voting yes would disqualify legislators with 10 unexcused absences for the term "following current term in office."