WASHINGTON — The Capitol loomed behind Senator Elizabeth Warren last week as she raised her fist to a crowd of union workers and promised to fight against one of the world's most expansive trade deals.
The cheers by labor and environmental groups in Washington were met with silence by companies back in Massachusetts, where the state's thriving life science and tech sectors consider the trade pact critical to the region's economic prosperity.
This disconnect pits Warren and some in the Democratic delegation against the state's key business groups as lawmakers consider legislation that would propel the deal forward.
"This [trade pact] is a huge opportunity not to be missed," said Christopher Anderson, president of the Massachusetts High Technology Council.
The dichotomy underscores deeper fault lines among Democrats about the role of free trade and its effects on American workers. The divide is particularly acute in Massachusetts, where Boston's surging technology, biotech, and medical device hubs contrast with postindustrial towns and their rising unemployment rates.
Warren has emerged as one of the deal's most vocal opponents, and she has made enough noise to attract the ire of the president.
"I love Elizabeth; we're allies on a whole host of issues," President Obama said Tuesday evening on MSNBC's "Hardball." "But she's wrong on this."
Warren, on Wednesday, shot back.
"The administration says I'm wrong — that there's nothing to worry about," she said in a blog post. "They say the deal is nearly done, and they are making a lot of promises about how the deal will affect workers, the environment, and human rights. Promises — but people like you can't see the actual deal." She declined an interview.
Committee leaders struck a bipartisan agreement last week to pursue a "fast track" bill that would allow Congress to vote on a trade accord but prevent members from amending it. The administration considers this essential to closing a deal on the Trans-Pacific Partnership, a pact with 12 nations in the Asia-Pacific region that could help counterbalance China's growing economic influence. It could also affect a later European trade deal.
The Trans-Pacific accord, intended to boost trade and economic opportunities among participating countries, would establish new rules on issues that include barriers to exports, intellectual property, labor standards, environmental protections, and food safety.
Nearly 365,000 Massachusetts jobs already are supported by trade with these countries, according to the Business Roundtable, an association of chief executive officers. Supporters argue these numbers will only increase. But many Democrats, wary of previous free trade promises, are skeptical of the administration's vow to protect American workers. Negotiations take place behind closed doors.
Warren stirred up more than 1,000 people at last week's rally when she cried, "Are you ready to fight?"
The Bay State senator has taken particular aim at a provision that she warns will allow multinational corporations to skirt US regulations. The process lets these businesses challenge governments in front of an international tribunal. If the company wins, the ruling cannot be appealed.
Administration officials have insisted the provision does not empower multinational corporations, noting that many trade deals include this structure.
Massachusetts business representatives also aim to prove the deal's worth.
"This is truly going to drive economic growth for decades to come," said Jim Klocke, the Greater Boston Chamber of Commerce's executive vice president. The group recently sent lawmakers a letter filled with data points about international trade's value to the Bay State.
The New England Council, an alliance that advocates for the region's economic growth, shipped the delegation a white paper that showed trade's impact on each state. And members of the Massachusetts Biotechnology Council made their support known last week at the organization's annual Washington pilgrimage.
But memories run long in Massachusetts, where some attribute the shrinkage of Lynn's General Electric plants to trade deals such as the North American Free Trade Agreement.
"Their jobs have been wiped out," said Steven Tolman, president of the Massachusetts AFL-CIO, which represents labor groups. "It's an incentive to take American jobs and put them in other places."
About 14 percent of Massachusetts workers participated in unions last year, according to the Bureau of Labor Statistics.
The national AFL-CIO has stopped making congressional contributions to pressure lawmakers into opposing fast-track legislation. The Coalition to Stop Fast Track, an alliance that includes labor groups, on Wednesday released its first ad in a seven-figure campaign to derail the legislation.
That leaves Massachusetts lawmakers caught between the interests of big labor and those of big business — and between Warren and Obama. Many are skeptical about rushing a deal they cannot even see.
"I haven't been convinced that working families and small businesses in places like Taunton, Attleboro, and Fall River are going to benefit," said Representative Joseph Kennedy III, a Brookline Democrat. "These cities can't continue to be an economic afterthought."
Senator Edward Markey, a Malden Democrat, warned such agreements will force Americans "to compete with nations that pay their workers dimes per hour."
Democratic Representatives Michael Capuano of Somerville and Stephen Lynch of South Boston refuse to support fast-track authority but have not ruled out voting in favor of the trade deal that finally results.
The debate has spilled into the 2016 campaign for the White House.
Hillary Rodham Clinton pushed the pact as secretary of state but has hedged as a presidential primary candidate trying to attract liberal support.
"Any trade deal has to produce jobs and raise wages and increase prosperity and protect our security," Clinton said Tuesday on a tour of the New Hampshire Technical Institute.
Former governor Martin O'Malley of Maryland, a possible presidential contender, on Tuesday released a video that criticized the accord. Senator Bernie Sanders, a Vermont Independent and possible candidate, also opposes the deal.
On Wednesday, Sanders invoked a Senate scheduling rule to delay committee action on the bill.
''This job-killing trade deal has been negotiated in secret,'' Sanders said. ''It was drafted with input by special interests and corporate lobbyists, but not from the elected representatives of the American people.''
Numerous Republicans are pushing for the pact and the authority to move it quickly. But those who have seen mills shuttered and factories close are less keen.
"Boy, do I have a lot of concerns," said Senator Susan Collins, a Maine Republican. "Is it going to create new jobs and opportunities or further decimate our manufacturing base?"