Where Oregon Senate races stand ahead of the primary

Half the seats in the Oregon Senate are up for election this year, and voters will send at least six new senators to Salem because of retirements and a law that barred most Republicans from running for reelection after they participated in a six-week walkout.

Control of the 30-member Senate isn’t on the line this election: Senators serve four-year terms with staggered elections, and most competitive races take place in midterm years. Democrats hope to add one or two new senators to their 17-member caucus, while Republicans hope they can...