Washington voters have rejected a measure that would have overturned the state's decadeslong ban on affirmative action — forcing state Democrats and advocates back to the drawing board.

"We're obviously disappointed," said April Sims, co-chair of Washington Fairness, the coalition that led the effort to approve the referendum. "But we remain committed to equity, opportunity and fairness — and that means a level playing field for everyone in Washington state."

As mail-in ballots continued to be counted in the days after the general election on Nov. 5, advocates remained cautiously optimistic that the measure — which was narrowly trailing for much of the week — would experience a late boost.

On Tuesday night, with voters rejecting the measure by less than 1 percent, Washington Fairness conceded.

Gov. Jay Inslee, a Democrat, said in a statement that the measure was an attempt to address "systemic inequities" that persist in work and education opportunities, and he will "continue to explore options that increase access to equitable opportunities and resources that reduce inequality."

Earlier this year, the state’s Democratic-controlled Legislature pushed through an initiative to restore affirmative action shortly before the legislative session closed, but opponents moved quickly to block the law with a referendum.

The political action committee Let People Vote opposed the Legislature's move and collected over 200,000 signatures to place the issue on the Election Day ballot, handing its fate over to Washington voters.

John Carlson, a political commentator who spearheaded the campaign to strike down affirmative action in Washington over two decades ago, said that the measure's passage would have been “unprecedented.”

“We've been moving in the direction of minimizing rather than magnifying race,” Carlson said in an interview before Election Day.

In 1998, Washingtonians passed an initiative that prohibited "preferential treatment to any individual or group on the basis of race, sex, color, ethnicity or national origin" within the public sector. It remains one of the nation’s longest-standing affirmative action bans.

Supporters of overturning the ban argued that since then, people of color have been discouraged from applying to public universities, and women and minorities have suffered from receiving fewer government contracts for their small businesses.

“This measure sent a strong message that Washington values fairness, and Washingtonians aren’t blind to the fact that the deck has been stacked against people of color and other marginalized individuals in our communities for decades, even centuries,” said Alison Holcomb, the political strategies director for ACLU of Washington.

However, Linda Yang, head of Washington Asians for Equality, voiced concern that the law would have adversely affected Washington’s Asian American community. She noted that in the absence of race-based affirmative action policies, 27 percent of the University of Washington freshmen enrolled this fall were Asian — compared with 8 percent of the statewide population.

"Our coalition of volunteers from across the political spectrum defeated [the measure] because voters didn't want a new system of quotas based on race, nor did they want a massive new unaccountable government bureaucracy to implement it," Yang said in a statement Tuesday night.

Asian Americans have recently become embroiled in the national debate surrounding affirmative action, with a high-profile lawsuit against Harvard alleging that its admissions process intentionally discriminated against Asian American applicants. In October, a federal judge ruled in favor of the university.

Currently, seven other states — Arizona, California, Florida, Michigan, Nebraska, New Hampshire and Oklahoma — have bans on affirmative action. In 2014, California considered repealing its ban, but efforts ultimately tapered out amid fierce pushback from Asian Americans, among other groups.

Advocates of affirmative action remain hopeful that such policies will eventually be restored in Washington and in other states across the country.

"We ran a campaign that we are really proud of," Sims said. "The results of this election show that nearly half of the folks who voted are ready to have that conversation, and we're prepared to engage with them."