Suzan DelBene, a former Microsoft corporate vice president, has brought her personal spending on the state's most-contested federal race to $1.9 million.

Suzan DelBene contributed another $900,000 to her campaign for the 1st Congressional District, bringing her personal spending on the state’s most-contested federal race to $1.9 million.

The new self-financing, which dwarfs the combined fundraising by her four fellow Democrats, allowed DelBene to up her TV advertising budget by $547,000, according to Thursday’s new Federal Election Commission filings.

DelBene, a former Microsoft corporate vice president, spent more than $2.2 million of her own money on an unsuccessful 2010 challenge of U.S. Rep. Dave Reichert in the 8th District.

One of DelBene’s primary Democratic challengers, Darcy Burner, said at a 1st District debate Wednesday that DelBene “would try to buy the election.”

Also competing in the top-two primary Aug. 7 are Republican Snohomish County Councilmember John Koster, who is ahead in many polls; Democrats Laura Ruderman, State Sen. Steve Hobbs and Darshan Rauniyar; and independent Larry Ishmael.

The district was redrawn last year, and political handicappers rate the campaign among the nation’s most-contested congressional races.