The Indiana's Senate passed right-to-work legislation Wednesday morning by a vote of 28-22, placing the state on the verge of becoming the Rust Belt's first to enact the contentious labor law.

The bill heads to Indiana Gov. Mitch Daniels, who has said he'll sign it.

As the streets of Indianapolis bustled with Super Bowl festivities, hundreds of union members gathered at the Statehouse to protest the legislation and planned a downtown rally that they hoped would point a national spotlight on what is happening in the state.

Indiana would be the first state in a decade to enact a right-to-work law prohibiting labor contracts that require workers to pay union fees. The Indiana victory is expected to embolden national right-to-work advocates, who have unsuccessfully pushed the measure in other states following a Republican sweep of statehouses in 2010. But few right-to-work states boast Indiana's union clout, borne of a long manufacturing legacy.

The vote in the Republican-controlled Senate, and Daniels' anticipated signature, will close one chapter in a contentious debate that sparked a five-week walkout by outnumbered House Democrats last year and saw them stage numerous boycotts this session, delaying action on other bills and threatening to spill over into the Feb. 5 Super Bowl.

But union protesters say they aren't ready to be silenced.

Chuck Wheeldon of Lafayette, wearing a Super Bowl 2012 baseball cap, said he was glad Indianapolis was hosting the game in a stadium that many of his fellow carpenters union members helped build.

"I don't want to ruin it for anybody, but I definitely want everybody around the rest of the country to know what the heck is going on," Wheeldon said. "If we cause a little ruckus, so be it."

Daniels said this week that it would be a "colossal mistake" for union protesters to disrupt Super Bowl festivities and that any such move could backfire on them.

Supporters say right-to-work helps create a pro-business climate that attracts employers and increases jobs. Opponents say it leads to lower wages and poorer quality jobs, and they accused Republicans of rushing the bill through to avoid disrupting the Super Bowl.

But with Republicans outnumbering Democrats in the House and Senate, and House Democrats facing stiff fines if they walked out for a lengthy period as they did last year, opponents have had few opportunities to stop the bill.

"We always knew this was going to be an uphill battle," said Indiana AFL-CIO spokesman Jeff Harris.

About 75 marchers weaved through packed crowds in the Super Bowl Village on Saturday to protest the measure, chanting "Occupy the Super Bowl" and carrying signs that read "Fight the Lie" and "Workers United Will Prevail."

Harris said protesters plan to hand out leaflets before Sunday's game.

Experts say many factors influence states' economies and that it's nearly impossible to isolate the impact of right-to-work. For major industries, access to supplies, infrastructure, key markets and a skilled work force are key factors, according to business recruitment specialists. For a state's workers, the impact of right-to-work is limited because only about 7 percent of private sector employees are unionized. Over the years, job growth has surged in states with, and without, right-to-work laws.

Business organizations and Daniels have pushed for the bill, claiming that many companies looking to expand won't consider Indiana because it isn't among the 22 states — mostly in the South and West — with a right-to-work law.

John Sampson, president of the Fort Wayne-based Northeast Indiana Regional Partnership, said Tuesday the economic development group would be making sure word gets out among its prospects about the change.

"We know some of the companies that turned us down overtly because we're not a right-to-work state, and we'll certainly go back to them and make pitches," Sampson said.

Business leaders and state economic development officials already have started talking about raising money for a "strong coordinated effort" to promote the state's changing status, said Indiana Chamber of Commerce president Kevin Brinegar.

Part of that work will begin this weekend as Daniels said he'll use activities surrounding the Super Bowl in Indianapolis to sell the state to visiting business executives. Private jets landing in the Indianapolis area also will leave with materials about Indiana's business climate, he said.

"We've always seen this as a great opportunity to do our most important job, which is to try to bring more employment here," Daniels told reporters this week.