By FRED BARNES

Ohio Gov. John Kasich likened himself last week to Bernie Kosar, the Cleveland Browns quarterback from 1985 to 1992. Mr. Kasich was campaigning across Ohio for approval of Issue 2, the troubled referendum that would sharply curtail the power of public-sector unions. Asked if his frenetic tour might trigger an upset, the governor responded impetuously: “We never thought Bernie Kosar would bring the Browns back and win that big championship game.”

But as Joe Vardon and Jim Seigel of the Columbus Dispatch reminded readers, Mr. Kosar “never won a championship game with the Browns, going 0-3 in AFC title tilt with trips to the Super Bowl on the line.”

Nor is Mr. Kasich expected to win on Issue 2. It’s probably the most important issue anywhere in the country when voters go to the polls in Tuesday’s off-year election. The outcome is likely to be a huge victory for organized labor, a setback for efforts to rein in government employee unions, and a boost for President Obama and Democrats in a key swing state.

Ohio Republican pollster Fritz Wenzel says Democrats and labor are “energized, excited, and above all organized as they never would have been without this issue.” While Mr. Wenzel’s survey in late October found support gaining for Issue 2, he thinks it will lose. A Quinnipiac poll on Oct. 25 showed it trailing by a whopping 57%-32%.

It didn’t have to be this way. When Mr. Kasich took over as governor after a narrow 2010 election, he faced a $8 billion deficit, a work force that had lost 400,000 jobs over the previous four years, and 3,000 local governments and entities with soaring employee costs and rising taxes.

With deep spending cuts, he balanced the budget without a tax hike. He initially wanted the curbs on unions to be enacted separately or attached to the budget. But the legislature, with lopsided Republican majorities in both houses, packaged the sweeping reforms in a single, 302-page bill known as Senate Bill 5.

It limited (but didn’t eliminate) collective bargaining by public unions, freed nonunion workers from paying union dues, stopped the automatic withdrawal of dues from paychecks, made it easier to decertify unions, forced employees to pay at least 15% of their health-care premiums and 10% of their wages for pensions, halted automatic yearly salary increases, and introduced merit pay.

This breathtaking assortment of reforms not only proved to be instantly unpopular—opposed by 51%-38% in a Wenzel poll—but it also instigated a furious union drive to repeal the whole package.

After suffering defeats in Wisconsin, Indiana and New Jersey, public employee unions were poised to take a stand in Ohio. Their coalition, We Are Ohio, immediately began collecting the 231,000 signatures to get repeal on the ballot. In July, the group delivered 1.3 million signatures. SB5 became Issue 2 on the ballot.

While the unions mobilized, Mr. Kasich turned to passing his budget. “It was the centerpiece of everything John wanted to do,” a Republican official says. Mr. Kasich, chairman of the House Budget Committee in Washington from 1995 to 2000, was willing to sacrifice popularity to get his agenda approved.

“The unions got out ahead,” state Sen. Keith Faber told me. “They had the ability to assess members and spend money right away.” With outside help from unions like the National Education Association ($2 million), Issue 2 foes have raised $30 million and out spent Building a Better Ohio, a business-funded group, which promotes a “yes” vote on the referendum, by roughly 3 to 1.

They’ve also outhustled supporters of Issue 2, setting up 35 field offices and boasting of 17,000 volunteers. When Mr. Faber told Mr. Kasich that union officials from around the country were flocking to Ohio, the governor said he hoped they would spend a lot of money as tourists.

The unions have a decided edge in intensity. “When unions get involved, they strike first and fight to kill,” says Frank Luntz, a long-time Kasich adviser. “They’re fighting for their life.”

Most important of all, the “no” forces are shaping public perception about the stakes, according to Quinnipiac pollster Peter Brown. They’ve made it “about union rights and whether the governor and the legislature were trying to kill unions.”

The TV ads by We Are Ohio, which have dominated the Ohio airwaves for months, stress the prohibition on unions’ ability to negotiate staff levels for police, firefighters and teachers. They suggest Issue 2 would put Ohio citizens in danger.

In one ad, a paramedic says emergency teams would face “slower response times because [Issue 2] makes it illegal to negotiate for enough crew to do the job.” Another says Issue 2 “places our police and our communities at risk.”

No doubt intentionally, these ads miss the point of Issue 2. It’s aimed at reducing the cost of local government and the burden on taxpayers. Without it, layoffs of employees, including police and firefighters, are inevitable.

After avoiding the subject for months, the pro-Issue 2 spots have taken on the central issue of government employees as a class. “Had enough?” begins an ad that pictures Ohio as a giant slum. “Without Issue 2,” a narrator says, “hard-working Ohio families will face higher taxes to pay for the excessive wages and benefits of government employees who already make 43 percent more than the rest of us.”

The Issue 2 struggle offers a few consolations for its advocates. Significant parts of it are popular, polls have indicated. In a Quinnipiac poll, for instance, by large margins voters would require government employees to pay more for health insurance, (57% for and 34% against) and pensions (60%-33%), and they prefer merit raises to seniority-based pay increases (49%-40%).

Nevertheless, even if Issue 2 wins in an upset, Mr. Kasich will have gotten “a black eye” from the fight and “angered a significant sector of the Ohio citizenry,” Mr. Wenzel says. But he has three years to recover before facing re-election in 2014.

Meanwhile, Mr. Obama may not be helped as much as Democrats think. While killing Issue 2 would help energize his base, it will do nothing to revive the state’s economy, or put unemployed Ohioans to work by next November.

Mr. Barnes is executive editor of the Weekly Standard and a commentator on Fox News Channel.