LANSING, Mich. — Over the shouts of thousands of angry protesters gathered outside the State Capitol here, Michigan's House of Representatives on Tuesday approved a bill that would vastly reduce the power of organized labor in this traditionally strong union state.
The 58-to-51 vote was the first piece of a two-part package, that would, among other things, bar workers from being required to pay union fees as a condition of employment.
"Recall! Recall! Recall!" union supporters cried out from the gallery.
Before the vote, Democrats in the state's House of Representatives, where Republicans hold a 64-to-46 majority over Democrats, were desperately trying to offer amendments to the measures in order to derail them. Among the suggestions: Send the question to a public vote. So far, all amendments had been rejected.
"This is being forced down peoples' throats," said Jon M. Switalski, a Democrat, speaking against the legislation. "It's being done so in a very poor way — in lame-duck with no committee meetings."
Democrats, one by one, recalled their family histories in labor unions and reminisced about what unions once meant to the country, but primarily, they talked about their objections to the speed and method of the Republican-sponsored legislation.
Joan Bauer, a Democrat, said she was saddened and sickened by what was happening.
"I cannot believe this legislations was rammed through in one day," Ms. Bauer said.
But Rick Olson, a Republican, said the legislation was a matter of worker choice, not of harming unions. Mr. Olson described the move as "tough love" for unions.
As the debate continued, the Capitol was closed after the authorities said the building had reached its capacity, leaving noisy union members — many dressed in red — on the lawn outside.
They chanted, the sound of their drums becoming increasingly loud: "Kill the bill! Kill the bill!"
Streets around the Capitol building were closed to traffic and numerous clusters of state police, some carrying riot gear, kept posts throughout the building and along nearby streets. At least two school districts around the state announced that they would close for the day, as word spread that teachers and other workers planned to protest in Lansing.
Democrats, including President Obama, have denounced the measures. Final passage requires votes by the State House of Representatives on two measures — one dealing with employees at private companies, the other with most public workers — and a signature from Gov. Rick Snyder, which is expected later in the week.
"You know, these so-called right-to-work laws, they don't have to do with economics," said Mr. Obama, during a visit to a truck factory outside Detroit on Monday. "They have everything to do with politics. What they're really talking about is giving you the right to work for less money."
From a distance, there would seem no more unlikely a target for this fight than Michigan, where labor, hoping to demonstrate strength after a series of setbacks, asked voters last month to enshrine collective bargaining into the State Constitution.
But that ballot measure failed badly, and suddenly a reverse drive was under way that has brought the state to a moment startling in its symbolism. How the home of the United Automobile Workers finds itself close to becoming the 24th state to ban compulsory union fees — and only the second state to pass such legislation in a decade — is the latest chapter in a larger battle over the role of unions in the nation's midsection.
It is a reflection of mounting tension between labor leaders and Michigan Republicans who took control of the state two years ago, and the result of a change of position by Mr. Snyder, a political novice who had long avoided the issue because, he had said, it was too divisive. It is also an effort being closely watched — and fueled, labor leaders say — by national conservative groups who see the outcome in Michigan as an emblem for similar measures in other states with far thinner union histories.
"Everybody has this image of Michigan as a labor state," said Bill Ballenger, the editor of Inside Michigan Politics. "But organized labor has been losing clout, and the Republicans saw an opportunity, and now the chickens are coming home to roost."
Since the wave of Republican wins in 2010 in statehouses in the Midwest, campaigns to limit unions have boiled over in Wisconsin, Ohio, Indiana and elsewhere. But in Michigan, where Republicans also won control, those efforts had seemed more muted, with some in the party, including Mr. Snyder, shying away from the broadest, most sweeping measures.
As it has throughout the country, membership in unions has fallen here in recent decades — about 17.5 percent of Michigan residents are members — and the statewide ballot proposal failed by 14 percentage points on Nov. 6, even as Mr. Obama won the state.