More than 60 percent of voters were rejecting vouchers, with about 95 percent of the precincts reporting, according to unofficial results. The referendum failed in every county, including the conservative bastion of Utah County.
Voucher supporter Overstock.com chief executive Patrick Byrne - who bankrolled the voucher effort - called the referendum a "statewide IQ test" that Utahns failed.
"They don't care enough about their kids. They care an awful lot about this system, this bureaucracy, but they don't care enough about their kids to think outside the box," Byrne said.
Doug Holmes, a key voucher advocate and contributor, said, "We started hugely in the hole and it's always been the case. The unions have done this in four different states, where they take the strategy of confusion to the people."
But Holmes said, "You don't run away from something because the odds are stacked against you."
Utah's voucher program, supported by Gov. Jon Huntsman Jr. and Republican legislative leaders, attracted national attention because it would have provided tax-funded subsidies to any student, rich or poor, to enroll in a private school.
The law passed by a single vote in the Legislature, but voucher opponents, led by the Utah Education Association teachers' union, gathered 124,000 signatures to force it into a voter referendum.
The resulting public opinion campaign included thousands of TV and radio spots and burned through $8.5 million for a program the state estimated would cost $5.5 million in its first year.
The tidal wave of cash changed few minds, however. As far back as January - before the Legislature approved the voucher program - a Tribune poll showed voters opposing vouchers 57 percent to 33 percent.
Had it passed, the plan would have offered tax-supported subsidies of $500 to $3,000 - depending on family income - for each newly enrolled private school student. It would have been the country's broadest voucher program because it would have had no income ceiling - all Utah students would be eligible as the program phased in over 13 years. By the end of the phase in, the program was projected to cost taxpayers $430 million.
Most of the opposition's $4.4 million came from the National Education Association and state teachers' unions from Florida to Alaska. Voucher supporters countered with more than $4 million, nearly three-quarters of that from Byrne and his family. Byrne says vouchers are the only way America's "broken" public education system can stay competitive with other industrialized nations.
"What's got to happen and it might take Utah five to 10 years to understand," Byrne said, "they are at the bottom of the heap [educationally] and the heap is at the bottom of the international heap."
He shrugged off the fortune he poured into the referendum, saying he leads a fairly modest life as far as CEOs go. "The fortune that I'm making is all going toward educating lower income and especially African-American and Hispanic kids," Byrne said. "So this is not a terribly big deal to me."
Supporters argued the program would help Utah absorb a tide of 150,000 children expected over the next 10 years by diverting students into private academies.
The clash quickly became superheated, with voucher opponents warning the program would bleed needed money from the public system, which already ranks last in the nation for per pupil spending and teacher pay. In television and radio spots, they hammered home a message that the program had "too many loopholes and unknowns."
Supporters fired back, connecting their opposition to liberal icons such as the American Civil Liberties Union, Sens. Hillary Clinton and Ted Kennedy and out-of-state unions. Meanwhile, other media thrusts implied that good Mormons should support vouchers.
Both sides, at one point, embraced the governor, who Byrne blasted Tuesday for his lukewarm backing.
"When he asked for my support [for governor] he told me he is going to be the voucher governor. Not only was it his No. 1 priority, it was what he was going to be all about," Byrne said. "He did, I think, a very tepid job, and then when the polls came out on the referendum, he was pretty much missing in action."
Byrne said the referendum defeat may have killed vouchers in Utah, but "There are other freedom oriented groups in other states - African-Americans in South Carolina are interested in it."
* Lisa Schencker and Robert Gehrke contributed to this report.