OLYMPIA — Democratic U.S. Sen. Maria Cantwell and Republican Susan Hutchison will face off in November for a Washington Senate seat.Cantwell, who is seeking her fourth term, easily outpaced all other candidates in the Tuesday Democratic primary. Under Washington’s primary system, the top two vote getters go on to November, regardless of party. Cantwell is Washington’s junior senator and the ranking member of the Energy and Natural Resources Committee. Hutchison, a former GOP state party chair, was finishing second in the voting in Tuesday’s contest.In a closely watched open congressional race in the state, Republican Dino Rossi was leading on a crowded ballot as he looks to advance to November. Rossi is a former state senator who had unsuccessful runs for governor and U.S. Senate.Incumbent Republican U.S. Rep. Dave Reichert is retiring from the 8th Congressional District after more than a decade. Among the dozen candidates on the ballot, one of three Democrats are expected to advance: pediatrician Kim Schrier, attorney Jason Rittereiser, or former federal public-health official Shannon Hader. Schier took an early lead among the group Tuesday night for the second spot, followed closely by Rittereiser.Washington is a vote-by-mail state, and voters had a deadline of 8 p.m. to have their ballot postmarked or placed in a drop box. In some of the more competitive races, results may not be known for days as most counties will update vote counts only once a day.District 8 includes Seattle’s eastern suburbs of Sammamish and Issaquah, which have seen their populations grow on the back of Microsoft, Google and other expanding technology companies. The district also includes more rural economies that are heavily dependent on agricultural exports.