Civil rights leaders fear a voucher program would merely subsidize private schools and affluent families who can already afford to send their children there, depriving the state's public schools of needed funding while helping schools that charge tuition most families couldn't afford even with a voucher.

"We don't want to see that happen," Williams said. "It would be going back to segregated schools. It would be looking at the haves and the have-nots."

Utah spent less money per student on education than any state in the country in 2005, the most recent year for which census figures are available.

"In terms of a voucher program, you may have created broad access for a very small pool of students of color, but overwhelmingly the majority of them still don't have access to quality teachers, rigorous curriculum and all the things conductive to a quality education," said Tammy Johnson, director of race and public policy programs for the Applied Research Center, a think tank focusing on racial justice that is based in Oakland, Calif.

"The reality is that the voucher program will never serve the majority of the population, especially people of color. It isn't set up to do that."

But Leah Barker, spokeswoman for Salt Lake City pro-voucher group Parents for Choice in Education, said it's minorities and low-income families who will benefit the most from the voucher program. About 83.5 percent of the state's population is white, with Hispanics making up the largest minority at about 11 percent. Blacks make up about 1 percent of the population, according to census figures.

"If you're trapped because you can't afford a better neighborhood or you can't afford a private school, this is going to be a ticket out," she said. "How much more segregated can we possibly be? All the low-income families live in the west side (of the Salt Lake Valley) and attend failing schools. We are segregated right now based on income."

But critics point out that private schools can turn away students for any reason they choose, and space is limited.

"The majority of students are going to be in public schools, so why aren't we dealing with that reality? If you look at the changing demographics of the nation, the younger the demographic, the more likely they are to be students of color. But all of a sudden you see this great divestment. That's why a voucher program is institutional racism," Johnson said.

However, Galey Colosimo, principal of Juan Diego Catholic High School, doesn't buy that argument. He sees private schools as a needed option for students who aren't succeeding in public schools. Although someone could be rich, he doesn't think the vouchers are an incentive for them to leave public schools and come to a private one. If anything, he said the voucher program will help diversify private schools.

"Whether they be minority or not, the wealthy are not going to be attracted to private schools based on the incentive of our voucher program. To the extent minorities are poor, I think they will be attracted," he said. "I just don't understand the logic of it. Whether you're from the NAACP or any organization that cares about allowing parents to be involved and direct their children's education, you ought to support the voucher program."