Sen. Patty Murray Has Slim Lead in Wash. State

Nov. 2: Sen. Patty Murray, D-Wash., speaks at an election night party for Democrats in Seattle. (AP)

OLYMPIA, Wash. -- Democratic U.S. Sen. Patty Murray took a slim lead over Republican challenger Dino Rossi in Tuesday's early vote returns, raising the possibility of an extended vote count in Washington's vote-by-mail election.

Murray had about 51 percent of the vote to Rossi's 49 percent in unofficial returns. More than half of the expected vote had been counted Tuesday night, but it can take several days to receive and tally all the ballots working their way through the mail.

At a Seattle rally, an optimistic Murray told supporters that she expected to pull away as more votes are counted.

"We are winning tonight, and we are going to win even bigger tomorrow," Murray said.

Rossi, who lost the 2004 governor's race by just 133 votes, emphasized that plenty of tallying remained.

"Unfortunately, we don't know what's going to happen in this race yet," Rossi told supporters in Bellevue. "There's still a lot of ballots to count, you know. But it's Washington state. What are you going to do?"

Presumed nearly unbeatable when her re-election campaign started, Murray drew a top-tier challenger in late May when Rossi bowed to national Republican recruiting efforts. The two were essentially guaranteed to face each other in the general election since Washington's nonpartisan top-two primary system favors broadly known candidates.

Murray was seeking a fourth term. The self-described "mom in tennis shoes" rose to power after an improbable first victory in 1992, becoming a budget subcommittee chairwoman and No. 4 in the Democratic leadership.

In a difficult year for the national Democratic agenda, Murray didn't flee from her powerful position. Instead, she chose to repeatedly remind Washington voters of the specific projects her influence has won from the "other" Washington.

The list was seemingly endless: A bridge fix in south Seattle, a veterans' hospital in Walla Walla, port construction money in Vancouver, critical dam repairs on the Green River.

She also painted Rossi as a tool of wealthy interests, pointing especially to his stance that Congress should repeal recent Wall Street regulatory reforms.

Kris Pope, of Shoreline, described herself as an independent voter. Pope said she had a hard time with the Senate race, but ultimately voted for Murray.

"I know a lot of people wanted a fresh start, but the president has a lot of things that he's started and I'd like to see him be able to continue that," Pope said.

Rossi was making a third stab at statewide office. He's well-known from two failed races for governor in the past six years, including the historically close 2004 contest. He left his real-estate investment business and challenged Murray after national trends appeared to tilt further in the GOP's favor.

Rossi has steadily run against Murray's federal spending and support for major Democratic initiatives, particularly the national health care bill and economic stimulus. Rossi also pitched himself as both a businessman and a capable lawmaker, recalling his role in balancing a major budget deficit at the state Legislature before his first run for governor.

He was betting that unease over the still-sputtering economic recovery would trump any voter doubts about dumping a long-serving senior senator.

Aileen Bouchee, 77, of University Place, said she voted for Rossi to push for a change in national policy amid the weak economy.

"I don't know that I could say that I was a Democrat or a Republican, or either," she said after dropping off her ballot. "All I could see is that it's not working the way that it is."