Brian Sepe has been a dues-paying member of the United Steelworkers for over three decades. Last week, he voted for Donald Trump in Massachusetts' Republican primary.

“My country is going to hell,” said Sepe, a 55-year-old utility worker and resident of Lowell, the famed mill town that is now one of the state’s poorest cities. “You look back at all the different trade agreements over the past 30 years, [and] it’s always been to move jobs out of the country. That’s got us in so much trouble. We don’t have good jobs left in this country.”

“[Trump] is a no bulls--- kind of guy,” Sepe continued. “He calls it what it is.”

Sepe belongs to a breed that’s causing serious concern among officials from organized labor and the Democratic Party: union members who support billionaire real estate mogul Trump for president.

As primaries and caucuses have illustrated thus far, voters across the country are drawn to the GOP front-runner’s populist rhetoric and tough talk on trade — both of which are pillars of many embattled U.S. labor unions. Come November, some Democrats and labor officials worry that Trump could capture a large chunk of the union vote, historically a vital part of the Democratic electoral coalition.

Mary Kay Henry, president of the 2 million-member Service Employees International Union, acknowledged as much in a recent interview. "I am deeply concerned about what is stirring, even in our membership ... where our members are responding to Trump's message," she told former Obama campaign strategist David Axelrod in a January interview.

The head of the AFL-CIO, the nation's largest labor federation, struck a similar chord in a speech earlier this month: "Donald Trump is tapping into the very real and very understandable anger of working people," Richard Trumka told a gathering of construction unionists. "When Trump says we’re losing, his message resonates with some folks. And when he yells or lashes out, he finds a sympathetic audience who wishes more politicians would express the frustration they feel."

Larry Cohen, a former president of the Communications Workers of America union who recently became a labor adviser to Democratic presidential candidate Bernie Sanders' campaign, told International Business Times he has witnessed firsthand how Trump’s rhetoric resonates with some union members on the campaign trail. Without Sanders and his brand of left-wing populism in the race, rank-and-file support for Trump would be even greater, he said.

“I think you have to look not just at the Clintons but [also at] the migration of the Democratic establishment in and out of finance capital, their families, their contributions, the way they combine social liberalism with free market economics and some lip service to workers’ rights but deliver nothing,” Cohen said. “People have had it with that liberal establishment.”

To be sure, a minority of labor-union households regularly vote Republican: 39 percent of voters from union households opted for John McCain in 2008 and 40 percent preferred Mitt Romney to President Barack Obama in 2012, for example. Among these GOP-leaning union households, limited polling suggests Trump is the hands-down favorite.

Sepe is one of these voters. Though registered as an independent, Sepe said he typically supports Republican presidential candidates. He said he likes Trump’s promises to crack down on illegal immigration and roll back unfair trade deals. He is not bothered by Trump's opposition to hiking the minimum wage or his support for so-called right-to-work policies, laws that prohibit unions from deducting fees from workers they represent but who decide not to join.

“Unions do still serve a purpose,” he said. “As far as [supporting] Democrats, I think they have to take a stand back and look over the years at how the Democratic Party has changed. It’s not the way it was when unions first started up. My belief is the Democrats, yes, they’re for the people -- but the people of what country? The highest bidder?”

Sepe blames the Democrats for the North American Free Trade Agreement, the hotly contested deal with Canada and Mexico championed by President Bill Clinton. He also blasted the Obama administration’s support for the Trans-Pacific Partnership, a similarly controversial agreement between the U.S. and 11 other Pacific Rim countries that would cover 40 percent of the world economy.

Michael Watson is another proud union member who backs Trump. Watson is a heavy highway contractor who sits on the advisory board of his Indiana district of Operating Engineers Local 150, a 22,000-member local that stretches from eastern Iowa to northern Indiana. The 46-year-old recalled voting for Republicans in recent presidential elections — and before then, supporting third-party bids from Pat Buchanan and Ross Perot.

He vehemently opposes his union’s decision to formally endorse Hillary Clinton —one of the roughly two-dozen nods from major unions that have gone her way, covering about 10 million members. Watson said the endorsement clashed heavily with the views of many members in his district, which counts a sizable contingent of Trump and Sanders supporters. “I think it’s bullcrap,” he said. “I don’t care for it.”

“I’m so tired of paying for freeloaders while they sit on their a-- while I have to work and take care of them, meaning illegal immigrants, people on welfare, able-bodied but won’t do anything to help themselves,” Watson said. “[Trump]’s not politically correct. I seem to have the same problem. I get tired of people’s feelings getting in the way of their thinking, and he speaks his mind.”

In addition to Republicans, limited anecdotal evidence suggests Trump may be picking up support from some Democratic-leaning union members: Jeff Hester, a former Democrat and currently laid-off member of the Teamster-affiliated Brotherhood of Locomotive Engineers who lives in Tennessee, recently launched his page Teamsters for Trump. It now counts more than 600 "likes."

When the Communications Workers of America union polled its members over who to endorse in 2016, Trump came in third behind Democrats Bernie Sanders and Hillary Clinton, winning more than was expected for a Republican candidate. The union eventually endorsed Sanders.

In January, the AFL-CIO affiliated Working America group polled likely voters with household incomes of $75,000 or less in working-class neighborhoods outside Cleveland and Pittsburgh. While most support for Trump came from Republican voters, one in four Democrats surveyed said Trump was their top choice.

Despite the many grumblings and anxieties, however, there is less hard evidence —at least, at this stage of the campaign — that Trump is actually gaining traction from union members who do not typically vote Republican.

A January 2016 poll from Zogby Analytics found Democratic presidential candidate Hillary Clinton leading Trump among union households by a 56-37 percent margin. In a Siena College Research Institute poll released Monday, union households in New York preferred the two Democratic hopefuls to Trump by wide margins, around 20 percent in both cases. Sixty-seven percent of New York union households held unfavorable opinions of Trump, the same poll found. Just 28 percent had favorable opinions.

Kate Bronfenbrenner, director of labor education research at Cornell University’s School of Industrial and Labor Relations, pointed to President Obama’s successful elections in 2008 and 2012. In both cases, concerns that union members would not back the campaigns failed to come to fruition, she said. Instead, union voters helped deliver Obama victories in crucial states like Pennsylvania and Ohio.

As Trump targets this crop of largely white voters, Bronfenbrenner said unions will have to put in the time and resources to counteract his appeal among rank-and-file members — just as they did against McCain and Romney.

“The labor movement was successful in getting these same voters to vote for Obama,” said Bronfenbrenner. “They’re going to have to get out there and do that kind of education again ... What happens depends on unions doing the work to educate members.”

The face of organized labor is changing too. Despite lingering popular perceptions, most U.S. union members today are not white men. Nearly half of all union members are in the public sector — which, on the whole, has a higher share of female and black workers than their counterparts in the private sector. And as research from Bronfenbrenner has shown, most new union members today are women and people of color. Voters from such backgrounds are unlikely to support Trump, she said.

“He’s targeted his campaign toward appealing to the fears of white men, but he is alienating a great deal of women and he’s totally alienating people of color,” Bronfenbrenner said. “And if that works in this country, if that works, then it is very frightening.”