OLYMPIA, Wash. (AP) — Democrat Manka Dhingra took an early lead Tuesday night in a state Senate race that will determine the balance of power at the Washington Capitol.

If the results hold and the Washington Senate flips, the state will join Oregon and California with Democratic one-party rule in both legislative chambers and the governor's office.

The first posting of ballots show Dhingra leading Republican Jinyoung Lee Englund with 55 percent of the vote. Under the state's vote-by-mail system, ballots just need to be postmarked or dropped off by Tuesday, which means that final results may not be known for days. The next ballot update is set for late Wednesday afternoon.

Republicans, with the help of a Democrat who caucuses with them, currently control the Senate by a single seat. Democrats hold a slim majority in the House.

Tuesday's race for the 45th District, one of eight special elections for the state Legislature this year, has broken all previous legislative spending records in the state because of the significance of the outcome. As of Monday, more than $8.7 million had been spent on the race, with much of it — about $5.9 million — being spent by third-party groups.

Englund said that because of the state's vote-by-mail system and the intense national focus on the race, she believes that many of the district's inundated voters got their ballots in later and that the gap will tighten as more votes are counted.

"This is a very big decision" for voters, she said. "The race isn't about me. It's about the balance of power."

But Dhingra said she was confident the results would hold, calling it "a victory by a very wide margin."

She said that while she believes voters had more than President Donald Trump on their mind while casting their ballots, she said she does believe that the national political environment helped energize voters.

"I think people are realizing they cannot be bystanders anymore," she said. "I think this is what you get when people are awake and paying attention."

Dhingra, a 43-year-old senior deputy prosecuting attorney with the King County Prosecutor's Office, also had a 10-point lead over Englund in August's top-two primary as both advanced to the November ballot. Dhingra was born in India, and her family moved to the U.S. when she was a teen. She oversees therapeutic alternative courts for the mentally ill and veterans and founded a nonprofit to address domestic violence in the area's South Asian community.

Englund, who is Korean-American, was previously a staffer for U.S. Rep. Cathy McMorris Rodgers of Washington as well as for The Bitcoin Foundation, a digital currency advocacy group, and worked on projects for the military.

The two political newcomers were seeking to serve the last year of a four-year term left vacant by last year's death of Republican Sen. Andy Hill. The winner will need to run again in 2018.

There are four other special elections in the Senate, and three in the House, though none of those races are expected to change the current balance of power in the Legislature.