Updated

A ballot battle in Ohio that pits the union rights of public workers against Republican efforts to shrink government and limit organized labor's reach culminates Tuesday in a vote with political consequences from statehouses to Pennsylvania Avenue.

A question called Issue 2 asks voters to accept or reject a voluminous rewrite of Ohio's collective bargaining law that GOP Gov. John Kasich signed in March, less than three months after his party regained power in the closely divided swing state.

Thousands descended the Statehouse in protest of the legislation known as Senate Bill 5, prompting state officials at one point to lock the doors out of concern for lawmakers' safety.

The legislation affects more than 350,000 police, firefighters, teachers, nurses and other government workers. It sets mandatory health care and pension minimums for unionized government employees, bans public worker strikes, scraps binding arbitration and prohibits basing promotions solely on seniority.

By including police and firefighters, Ohio's bill went further than Wisconsin's, which was the first in a series of union-limiting measures plugged by Republican governors this year as they faced deep budget holes and a tea party movement fed up with government excess.

Democratic governors, including New York's Andrew Cuomo and Connecticut's Dannel Malloy, have also faced down their public employee unions in attempts to rein in costs.

That's why labor badly needs a win in Ohio, said Lee Adler, who teaches labor issues at Cornell University's New York State School of Industrial and Labor Relations.

"If the governor of Ohio is able to hold the line on the legislation that was passed, then it would be a very significant setback for public sector workers and public sector unions in the U.S.," he said. "Likewise, if the other result happens, then it would certainly provide a considerable amount of hope that, with the proper kind of mobilization and the proper kind of targeting, some of the retrenchment that has been directed at public sector workers can be combated."

Victory could also galvanize support and build energy within the Democratic-leaning labor movement ahead of the 2012 presidential election, a potential boon for President Barack Obama's re-election effort.

We Are Ohio, the labor-backed coalition fighting the law, had raised more than $24 million as of mid-October -- more than Obama, John McCain and 18 other presidential contenders raised in combined Ohio contributions during the 2008 presidential election, according to Federal Election Commission data.

Building a Better Ohio, the business-fueled proponent campaign, has raised $8 million. Outside groups including FreedomWorks, Americans for Prosperity and the Virginia-based Alliance for America's Future are also rallying support for the law. Their spending hasn't been documented.

"This will eclipse any statewide candidate election in the history of the state, in terms of spending," said Jason Mauk, a spokesman for Building a Better Ohio. "It's an unprecedented campaign."

Ohio voters favored repeal 57 percent to 32 percent, an Oct. 25 Quinnipiac University poll showed. But Mauk said the law's backers are still cautiously optimistic they can win, and will continue through the weekend to carry the bill's tea party-friendly message to voters.

"People are tired of government spending more than it makes, more than it collects, and they're frustrated by the debt and deficit problem in Washington," he said. "Voters clearly sent a message of concern (in 2010) and they're demanding that government get its house in order, and that's the platform John Kasich ran on. This is an effort to try to eliminate government excess and get spending under control."

Kasich is ranked among America's least popular governors, thanks in part to his fight against the unions. The former congressman, investment banker and Fox News commentator has traveled the state to rally voters to keep the law and appeared in pro-Issue 2 commercials paid for by Make Ohio Great, a project of the Republican Governors Association.Voters are eager to help defeat the law because they felt disenfranchised by the process, said Melissa Fazekas, a spokeswoman for the opposition.

The bill was introduced, debated in the Legislature, passed and signed by Kasich in two months. GOP legislative leaders say they heard dozens of hours of testimony and Democrats proposed no amendments to the bill during deliberations.

After it passed, the law's opponents easily gathered 1.3 million signatures for their ballot effort and now boast a legion of more than 17,000 volunteers of all political stripes.

"I've never been involved in something quite like this," Fazekas said. "I've just never seen people so engaged and enthusiastic. I've seen situations before where people were willing to sign petitions, but on this issue people were literally grabbing petition booklets out of our hands and taking them out and circulating them."

Adler said public schools and the post office are the last two big government entities not controlled by corporations, and so are primary targets of union-limiting efforts.

He said "everybody A to Z" will be watching the vote's outcome because of the state's long history as a political bellwether: "Ohio tells a story about America every time it votes."