OLYMPIA, Wash. — Democratic Sen. Patty Murray expanded her small lead over Republican challenger Dino Rossi on Wednesday as officials counted more ballots in Washington state's slow-moving election system.
With about two-thirds of the expected ballots counted Wednesday evening, Murray led Rossi by about 51 percent to 49 percent. Her margin was roughly 25,000 votes out of the more than 1.5 million counted so far in unofficial returns.
Thousands of ballots still are being processed and will be counted in the days ahead, leaving the race too close to call. Particularly telling will be King County, the state's largest county and a Democratic stronghold, where Murray was leading with about 62 percent.
Both campaigns entered Wednesday's vote count saying they could maintain paths to victory. A win by Murray would improve Democrats' cushion in the Senate as Republicans take control of the House for the rest of President Barack Obama's term.
Nearly everyone in Washington votes by mail, and ballots may be mailed in through Election Day, leaving several days of processing and counting as envelopes postmarked as late as midnight Tuesday make their way to election officials.
State law would mandate a re-count if the margin is less than 2,000 votes. Washington has seen close races recently, including 2004's gubernatorial contest and Democrat Maria Cantwell's re-count victory over Republican Sen. Slade Gorton in 2000.
Murray's campaign for a fourth term featured a strong defense of her role in securing federal spending for Washington, highlighting the specific bridges, dams, highways, hospitals and construction jobs she helped deliver.
Rossi tried to turn those points against Murray, campaigning as a fiscal conservative who would forgo pet-project spending until the budget was balanced. He also criticized her support for Democratic overhauls of health care and Wall Street regulations.
Murray spent nearly $15 million through September to Rossi's roughly $2.5 million, but a flood of outside money helped Rossi keep up.