The Democratic-led House was poised Tuesday to pass legislation that would invigorate workers' unions, following decades of court defeats and legislative setbacks that have kneecapped the labor movement's once-formidable ability to organize.

But the measure, which union leaders and labor allies have presented as a cure for decades of working class wage-stagnation, faces an all-but-certain Republican blockade in a narrowly divided Senate and is unlikely to become law.

“People know that corporations are too strong and workers aren’t strong enough,” said AFL-CIO President Richard Trumka, who dismissed concerns that the bill couldn't pass the Senate. “Those who side with (corporations), I think do so at their own peril.”

The Democratic push comes in the midst of a massive organizing drive in the historically labor resistant South, which offers a crucial test for a labor movement that is showing new signs of life after decades of atrophy.

President Joe Biden previously pledged to be “the most pro-union president you’ve ever seen.” He recently gave union organizers at a 6,000-worker Amazon facility near Birmingham, Alabama, his tacit endorsement in an unprecedented sign of support. He also endorsed the Democratic bill.

Democrats are looking to fortify bonds with rank-and-file union members, a key constituency that has been critical for getting out the vote. Some drifted toward the GOP under President Donald Trump despite the Republican Party’s long antipathy toward unions — attracted to Trump's “America First” agenda and his hostile stance toward global trade.

While Republicans have welcomed blue-collar workers drawn to the party by conservative cultural issues, many draw the line at measures that would expand the power of labor.

“I’ve heard Democrats argue that it’s the unions that built the middle class,” said Rep. Virginia Foxx, R-N.C., the senior Republican on the House labor panel. “No, the unions didn’t build the middle class. Entrepreneurs and individual workers in this country built the middle class. And what this bill does is take away their freedom.”

Labor unions have long been a bedrock of Democratic support. But as the number of unionized workers has dwindled over recent decades, so too has labor's power.

It's a collapse that Republicans urged on at the state-level through the passage of so-called Right to Work laws, which crimped unions’ ability to collect dues from workers who refuse to join, yet benefit from deals negotiated on their behalf. Rep. Hakeem Jeffries of New York, the No. 4 House Democrat, said there has been an "unrelenting attack on the ability of everyday Americans to organize themselves."

Critics and supporters alike agree the House measure would reverse such laws. It would also bar tactics that employers can use to drag out organizing drives, contract negotiations and ultimately the ratification of an agreement.

Other provisions of the bill include:

— Giving organizers more control over how — and where — unionization votes are held, allowing them to be conducted at arms-length from employers who may be hostile to the effort.

— Empowering the National Labor Relations Board to fine companies that fail to comply with orders from the board.

— Granting organizers access to the contact information of workers, who they then could reach outside working hours during unionization drives.

— Among dozens of other provisions, it would also prohibit companies from hiring replacements for workers on strike, prevent some workers from being classified as “independent contractors” to avoid unionization, and forbid employers from forcing workers into “captive audience meetings” where unionization is discouraged.

Unions have historically offered a pathway to higher wages. But during floor debate, Republicans focused on the longstanding political relationship between Democrats and labor.

“This far recaching legislation is nothing more than an union boss wish list,” said Foxx, who led Republican debate on the bill.

Virginia Republican Rep. Bob Good excoriated the bill, saying it would effectively “funnel money to Democrats” by allowing unions to collect additional dues.

But the debate also presented an awkward counterpoint to those in the party who have seized on Trump's appeal to white working class voters and sought to rebrand the GOP, long a bastion of business and country clubs, as a working-class party.

“They haven’t done a thing today to prove they care about workers,” said Rep. Mark Pocan, D-Wis. “It’s this side of the aisle that’s doing all the heavy lifting.”