Colorado voters have narrowly rejected a ballot measure that would have banned affirmative-action programs based on race, gender, and national origin at public colleges and other state agencies, the Rocky Mountain News reported.

The results mark the first time that a state’s voters have rejected such a ballot measure, with implications for admissions and other decisions. The outcome of Tuesday’s vote had been too close to call until this afternoon.

The newspaper said that, with 96 percent of the precincts reporting, 50.6 percent of Coloradans had voted no while 49.4 percent had voted yes. The difference was less than 25,000 votes out of more than two million cast.

Supporters of the measure, however, refused to concede defeat. Jessica Peck Corry, a spokeswoman for the Colorado Civil Rights Initiative, which supported the campaign, told The Denver Post that to concede before all the votes were counted “would be a disservice to the more than one million voters who supported” the measure.

Nebraska voters endorsed a similar measure on Tuesday. The proposals in both states were nearly identical to the ballot measure that Michigan voters approved two years ago. —Sara Hebel