Congressional candidates John Koster and Suzan DelBene are not running merely for a two-year term in the new 1st District, but also to serve the final month of Jay Inslee's term in the existing 1st District, which has a different political makeup.

1st Congressional District candidates John Koster and Suzan DelBene are in a tight race for a two-year term in Congress. They’re also in another race — not as close — to serve a single month in Congress at the end of this year.

The weird circumstance was brought on by former 1st District Rep. Jay Inslee’s resignation from the seat to run for governor. It means the two candidates are on the Nov. 6 ballot twice in some areas: Once in the newly redrawn 1st Congressional District, and again in the old 1st Congressional District to fill in for Inslee’s final month.

The old 1st District, which leans Democratic, included Seattle’s northern and eastern suburbs, Bainbridge Island and part of the Kitsap Peninsula. The new 1st, which runs north from Redmond to the Canadian border, is being touted as almost evenly split between Democrats and Republicans.

Koster, the Republican, had a stronger primary showing in the new 1st District than he did in the old. He would have to make up a lot of ground to beat DelBene, the Democrat, in Inslee’s 1st District: The old district supported Democrats Barack Obama for president and Chris Gregoire for governor in 2008.

Unlimited Digital Access. $1 for 4 weeks.

If the same candidate wins both 1st District races, he or she will have more seniority than other freshman members of Congress, which means a leg up on office and committee assignments. Whoever wins the one-month term will vote on key end-of-year budget issues.

Emily Heffter: 206-464-8246 or On Twitter @EmilyHeffter.