The move makes Indiana the 23rd state to prohibit labor contracts that require workers to pay union representation fees and the first to adopt such legislation in a decade.

“This law won’t be a magic answer, but we’ll be far better off with it," Daniels said in a statement. "I respect those who have objected, but they have alarmed themselves unnecessarily -- no one’s wages will go down, no one’s benefits will be reduced and the right to organize and bargain collectively is untouched and intact."

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

Shortly after the Senate passed the measure Wednesday morning, between 3,000 and 4,000 union protesters streamed outside chanting, "We vote, we remember," and "Take it to the streets," before marching into Super Bowl Village, down to near the stadium and back.

"This great movement in Indiana, they've tried to crush us by force, and we've survived it. This time, they're trying to crush us by a law. We can survive that, too," said Indiana AFL-CIO President Nancy Guyott told protesters. "They ain't seen nothing yet."

Tempers were high as the head of the building trades unions thanked members for showing up all month to unsuccessfully fight the bill.

"(We've been) fighting to send a message to these arrogant people that think that they can tell us how to live, where to live and what kind of living we can have. That's (expletive)," shouted Building Trades President Dale Johnsen.

Chuck Wheeldon of Lafayette was among those gathered at the state Capitol. He's said he's glad Indianapolis is hosting the Super Bowl in a stadium many of his fellow union carpenters helped build and said he doesn't want to ruin the big game for anybody. But he added, "If we cause a little ruckus, so be it."

Daniels said it would be a "colossal mistake" for demonstrators to disrupt Super Bowl festivities because of the potential backlash.

Daniels' signature closes 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 Super Bowl.