When Nathan Kecy graduated from Plymouth State University in New Hampshire a decade ago with a bachelor's degree in communications, he found himself with about US$10,000 in debt and few clear career options. He first found work as a door-to-door salesman ("a pyramid scheme", he recalls) and then in telemarketing. Finally he landed a job as an infrastructure specialist for Datamatic, a Texas-based water meter technology company.

He was travelling across the US installing meters, making a decent salary. But he lost his job after the company restructured in 2012, he said, and soon he found that his skills weren't easily transferable to a new field; Datamatic's technology was proprietary, and his expertise in the company's installation programme wasn't appealing to employers outside that particular industry. He tried going into business with a friend, but the relationship soured. By then he had a baby and a fiancee, and he felt stuck.

Now 32, Mr Kecy is a few months away from finishing a six-month certificate programme in advanced composites manufacturing at Great Bay Community College in Rochester, New Hampshire. The programme operates out of a satellite campus that opened in 2013, with aid from a Labour Department grant meant to help community colleges reach "trade displaced" workers who need help training for new careers.

The unemployment rate in southern New Hampshire is low, less than 3 per cent. At one state job fair last summer, just 350 people showed up for 1,200 jobs.

In Strafford County, where Rochester is located, the largest employers include the University of New Hampshire and Liberty Mutual, as well as manufacturers like Turbocam. Mr Kecy's classmates include veterans, recent high school graduates and older workers whose careers had reached dead ends. All of them are looking for hope and a decent pay cheque by acquiring a new set of skills.

"Within six months, I'm going to go from regular guy to working in the aerospace community," says Tommy Florentino, a disabled veteran with a background in construction and automotive manufacturing. He has friends who went to Boston College or Suffolk University, "and they're waiters and waitresses".

The college's 27,000 sq ft Advanced Technology and Academic Centre is at the edge of a nondescript shopping centre. The complex also houses a Dollar Tree, a JC Penney and a Kmart, where a banner out front reads, "Now hiring". Cashiers there earn close to minimum wage. But Mr Kecy expects to earn at least US$16 (S$22) an hour when he graduates, and to move up quickly from there.

Composites is a broad field in manufacturing, with applications including automotive parts, sporting goods and prosthetics, as well as in the locally prominent aerospace industry. The state's economic development department bills its seacoast region as "the emerging composites region", and it points to Great Bay's programme as a reason for more aerospace and defence businesses in particular to relocate there.

"I've got some options, which is something I've never really experienced before," Mr Kecy says.

There's a strange disconnect between two of the big narratives about the American blue-collar workforce right now. In one story, there is a population of unemployed and underemployed working-class adults for whom well-paying work seems increasingly out of reach; their jobs have gone overseas or become automated, and they find themselves working retail, or not working at all.

But an apparently conflicting story comes from US employers, who have been insisting for years that they have a hard time finding workers to fill skilled blue-collar jobs. A 2015 report from the Manufacturing Institute, for example, found seven in 10 manufacturing executives saying they faced shortages of workers with adequate tech skills. A high proportion of existing skilled workers is also nearing retirement, which means a bigger gap is looming soon. By 2025, the report warned, two million jobs will be going unfilled. (Healthcare, also a big focus of retraining programmes, is another rapidly expanding field.)

BRIDGING THE SKILLS-JOBS GAP

The tantalising promise of government-funded job training is that it can bridge the gap between those narratives in a way that benefits individual workers, employers and the country as a whole. Hard-working Americans get good jobs, employers get skilled labour and the economy benefits from their mutual good fortune.

The image of that virtuous circle has made the promotion of training programmes appealing for politicians on the left and the right. Democrat Hillary Clinton had proposed retraining former coal-industry workers in new careers as part of a US$30 billion package meant "to ensure that coal miners and their families get the benefits they've earned and respect they deserve". And even as Republicans voted to cut funding for training in recent years, they have paid it lip service as a way to put Americans back to work.

It's perhaps not surprising, though, that so much of the working class gravitated in the last election to Donald Trump, whose rhetoric about displaced workers was very different: blunt (if unrealistic) promises to stop old careers from disappearing, to "bring back our jobs". In its zeal for retraining, the federal government's approach to the problem has become increasingly byzantine, a dizzying constellation of programmes to help struggling workers prepare for new careers. Some of them are meant for employees laid off en masse when their jobs went overseas, and others are for those who are simply unemployed and underqualified for well-paying work.

In the 2009 fiscal year, the Government Accountability Office counted 47 federal training-related programmes run by nine agencies, numbers Republicans have since used to argue that many of the schemes were redundant. In his 2012 State of the Union address, even President Barack Obama criticised the "maze of confusing training programmes" unemployed workers had to navigate to get help. The Workforce Innovation and Opportunity Act, signed into law in 2014 with bipartisan support, was designed in part to streamline the government's approach.

Critics also say that job training is costly and too often ineffective. Take the primary federal effort aimed at workers affected by global trade, the Labour Department's Trade Adjustment Assistance (TAA) programme. Through TAA, qualified workers can get free retraining, typically through a community college scheme like Great Bay's.

It is a generous programme, spending more than US$11,500 on each person who participated in retraining in the 2015 fiscal year. But it serves relatively few people, and recent analysis has shown iffy results: A 2012 evaluation prepared for the Labour Department found that while 85 per cent of those who went through TAA-funded training eventually received a certificate or degree, only 37 per cent of them were working in that field four years later. (The programme was later amended to include more individualised support.)

All too often, sceptics say, publicly funded training programmes are a sop to well-connected companies which want taxpayers to foot the bill to train their workers. Critics also point at research suggesting that on-the-job training by employers themselves has been declining.

But it simply doesn't make economic sense for most employers to do all of their own training anymore. In part, this is because of technology: Jobs in advanced manufacturing and healthcare need intense technological instruction, usually accompanied by classroom time.

At the same time, standardisation means employers often poach skilled workers from one another, which discourages them from investing a lot of time and money in training their own workers.

"It's unrealistic today to think of traditional, very idiosyncratic manufacturing jobs where you're going to walk in, get a job, get trained in a bunch of very specific skills, and they'll hold onto you for decades," says Harvard University economist Lawrence Katz. "That's just not the trajectory of employment anymore."

DEMAND-DRIVEN TRAINING

After completing the certificate programme in April, Mr Kecy will have specialisations in "non-destructive testing" and "bonding and finishing", skills that set him up for specific positions that local employers have been struggling to fill. The simplest description of composites manufacturing is that it is the process of putting two materials together; adobe, for example, is a composite of straw and mud.

"Advanced" composites manufacturing typically involves adding high-tech resin to woven fibres. The strong, lightweight finished products are replacing metal in many manufacturing areas, including aerospace.

Great Bay students further specialise in areas like quality inspection or resin-transfer moulding; the goal is that when they graduate, they are ready for high-end entry- level jobs.

Advanced manufacturing in general is a strong industry in New England; a recent analysis by Deloitte and the New England Council found that in 2012, 59 per cent of the region's 641,000 manufacturing jobs were "advanced".

With his certificate, Mr Kecy is confident he will find a job locally, and he's probably right. Great Bay's composites programme was developed in a close relationship with Safran Aerospace Composites and Albany Engineered Composites, two companies that opened a shared plant in Rochester in 2014.

Safran helped develop the programme's curriculum and stays in touch about which specialisations it will be needing in the coming months. It guarantees interviews to all graduates of the programme and has hired about 30 of the more than 170 participants so far. Overall, more than half the programme's graduates have been hired by five large local manufacturers, says director Debra Mattson.

That level of coordination with local industry, ideally touching on everything from curriculum to recruitment, is now seen by policy experts as a crucial dividing line between programmes that work and those that don't.

The federal government now emphasises this kind of "demand-driven" training in part to ensure that workers aren't being retrained with new skills as obsolete as their old ones. "A good sign is if the programme was co-developed with the firm," says Mark Muro, a senior fellow at the Brookings Institution's Metropolitan Policy Programme. "One of the fundamental problems is training divorced from labour- market dynamics - people being trained without the presence of jobs they could actually arrive in."

(The Nordic countries, which spend more on job training in general, have a strong record in developing training with input from both industry and labour.)

The evidence in the US for demand-driven training is promising so far. A 2010 study of three such programmes found that enrollees were earning almost 30 per cent more than a control group two years after they began the programme and were significantly more likely to be employed.

The Great Bay programme has relationships with Safran, AEC and other area employers, including BAE Systems, Turbocam International and the gun manufacturer Sig Sauer, which recently landed a US$580 million contract with the Army. The programme is short by design, and new cohorts start three times a year to ensure a steady stream of graduates for local employers. "Industry is dying for bodies, just dying for skilled workers," says Great Bay's president Will Arvelo. "They can't wait two years."

On a snowy afternoon a few weeks ago, Mr Kecy and his classmates in his Fundamentals of Composites Manufacturing class were at work in the "clean room". The setting looked more like a science lab than a factory. A large cooler stacked with vacuum-sealed bags of thick fabric pieces stood in the corner, and work tables held clusters of metal tubes.

Class instructor Peter Dow watched as two teams of students worked on a project they had been planning for several weeks: constructing a three-inch carbon-fibre tube with a finished exterior. Later they would have a chance to tweak their plans and try it all over again, a lesson in the manufacturing principle of "continuous improvement".

For all the ways in which technology has changed the manufacturing industry, one of the most striking to an outsider is the appearance of the work space itself. The students in the clean room wore white coats and safety glasses as they used hair dryers and refrigerant spray to fiddle with the sticky material.

Outside their small work area, the facility's spotless manufacturing lab offered the capacity to build a product from start to finish: a huge, three-dimensional loom for weaving carbon fibre, a five-axis machining centre, an automatic autoclave. Practically every piece of equipment seemed to feature a keyboard or touchscreen.

HIGH-TECH MANUFACTURING

But manufacturing's new high- tech, high-skill profile is also what makes it daunting for many older workers looking for new careers.

The dilemma illustrates some of the broader challenges of retraining later in life. Kerri Uyeno, a 43-year-old single mother of three who graduated in the Great Bay programme's first cohort in 2014, began working at Safran as a bonding operator three weeks after earning her certificate. It was such a happy ending that she featured prominently in early publicity materials for the programme. But she had conflicts with her supervisors and lasted just over a year in the job before quitting. She didn't work again for six months; her house went into foreclosure.

An administrator at Great Bay tried to persuade her to return and work towards her associate degree, but the prospect was exhausting. "It was so hard to get through that six months to my certificate," she said, "I just didn't have it in me to get more schooling."

Today she is an office manager at a flooring showroom nearby. She still exudes pride when she talks about earning her certificate, but she also calls the experience "one of the biggest heartbreaks I've ever gone through".

At 49, Dean Kandilakis is one of the oldest students in the programme's current cohort. He has a master's degree in international relations, but he spent most of his career doing administrative work.

"There's a really large learning curve for someone who's just re-entering from a different field," he said during a break from class. "It's been a very stressful time for me, because it's an adjustment in my identity as a human being." But he said it's worth it to feel as if he's finally becoming a specialist in something.

It can take enormous intellectual and emotional efforts to pursue retraining, especially for people who have been rattled by sudden job loss or depressed by declining career prospects.

For all his grandiosity, Mr Trump's approach to working-class voters is characterised by relentless pessimism: dark visions of "poverty and heartache", warnings about Mexicans "taking our manufacturing jobs".

Nostalgia, with its disdain for the present and mistrust of the future, is really quite a gloomy sentiment. Job training, by contrast, makes the smaller-but-sunnier assurance that starting over is possible with help and time. It takes optimism on the part of policymakers and workers.

Back in the lab, Mr Kandilakis' team had been having some difficulty with their tube; the material was too warm, and it was thickening too quickly as they moulded it. "We're having some problems today," he said, but he didn't sound concerned. "Thankfully, we'll have another run." NYTIMES

•Ruth Graham is a contributing writer at Slate.