Donald J. Trump redrew the electoral map with his rousing economic nationalism and evocation of a lost industrial age. It was a message that drew many union members to his cause. And now it is upending the alliances and tactics of the labor movement itself.
In early November, workers at the Momentive chemical plant in upstate New York went on strike to beat back pension and health care concessions. By January, the workers were invoking some of Mr. Trump’s populist campaign themes — but with a twist. They planned to picket outside the Manhattan home of the billionaire Stephen A. Schwarzman, whose private equity firm until recently owned a share of the company, and whom Mr. Trump has appointed as an outside adviser on jobs.
“We used that angle — he’s one of the richest men in the country, has been appointed by Mr. Trump as the so-called jobs czar,” said Darryl Houshower, vice president of the local. “We were pressuring him, hoping he would put some pressure on the company.”
Whatever happened behind the scenes, they got the result they wanted. The day before the protest was originally planned this month, the company backed off a number of key demands. The workers ratified a new contract several days later.
The episode is just one sign of the sudden shifts buffeting the labor movement. Some unions, even if traditionally Democratic, have aims that align with Mr. Trump’s stated priorities: building infrastructure, rewriting trade agreements, blocking an exodus of jobs. But union leaders are in many cases scrambling to get in step with members who responded to his pro-worker rhetoric — and to tap into that energy.
Mr. Houshower’s local is affiliated with the Communications Workers of America, one of the unions most outspoken in their criticism of Mr. Trump since the election. But while he voted for Hillary Clinton, he estimates that some 30 percent to 40 percent of his more than 600 members voted for Mr. Trump.
“I think some of the things the president was saying during his campaign, you know, looking to make better jobs in America, bring work back to America, kind of pulled on the strings of the average worker,” Mr. Houshower said. “A lot of guys felt that he was the man to do the job.”
Such sentiments help explain why Mr. Trump came as close among voters from union households as any Republican presidential candidate since 1984. And they are the basis for an approach espoused by his top political adviser, Stephen K. Bannon, who has mused about a tectonic political shift that would rearrange traditional partisan allegiances around economic interests.
Surely no small benefit of that realignment would be to divide organized labor, a key Democratic constituency, and the White House has been shrewd about capitalizing on workers’ pro-Trump sentiment.
Mr. Trump summoned the heads of the building and construction trade unions, most of which supported Mrs. Clinton, to discuss infrastructure spending three days after his inauguration. “It was a substantial meeting about good middle-class jobs,” said Terry O’Sullivan, general president of the Laborers’ International Union of North America, adding that Mr. Trump was the first president to invite him to the Oval Office.
Some of Mr. Trump’s other early moves, like his presidential memorandums giving the go-ahead to the Keystone XL and Dakota Access pipelines and killing the Trans-Pacific Partnership trade agreement, and his announcement that he would quickly seek to renegotiate the North American Free Trade Agreement, were clearly conceived with a similar objective.
They appear to have had the desired effect. Dennis Williams, head of the United Auto Workers union, which endorsed Mrs. Clinton, has professed eagerness to meet with Mr. Trump to discuss how they might undo Nafta and protect American jobs.
“He’s the first president that has addressed this issue, and I’m going to give him kudos for that,” Mr. Williams said at a round-table discussion with reporters in Detroit on Thursday.
Other unions may also have reason to do business with the White House. Consider the International Association of Machinists and Aerospace Workers, which also endorsed Mrs. Clinton. Some portion of the union, namely its freight railroad workers, is heavily dependent on coal, and union officials say members in that sector voted heavily for Mr. Trump because he refused to foreclose on its role in the national economy.
In response, progressives have groused that some blue-collar unions are willing to sell their souls for a few thousand jobs. They say that members who enthuse about the president’s ostensible victories for workers, like his efforts to block the manufacturer Carrier from sending jobs to Mexico from Indiana, are utterly blinkered.
“Trickle-down economics dressed in populist garb is still trickle-down economics,” wrote Robert B. Reich, labor secretary under President Bill Clinton.
All in all, it is precisely the backlash that must delight the current occupants of the West Wing. Still, some labor leaders insist that they will not be so easily divided.
“I would not be surprised if Steve Bannon and others would be overtly and covertly trying to divide the labor movement,” said Randi Weingarten, president of the American Federation of Teachers. But she predicted that the effort would ultimately collapse under its own contradictions.
The week after Mr. Trump met with the construction trades unions about infrastructure, his press secretary, Sean Spicer, told reporters that “the president believes in right to work,” which would allow workers to opt out of paying union dues or fees. A national right-to-work law would thrill congressional Republicans but provoke near-uniform opposition from labor.
So would a bill recently introduced by Senator Jeff Flake, Republican of Arizona, that would suspend the Davis-Bacon Act, which requires the government to pay construction contractors prevailing local wages, specifically on federal highway projects.
For that matter, Mr. Trump’s own coalition is hardly a model of cohesion.
His first nominee to be labor secretary, the fast-food executive Andrew Puzder, won plaudits in the corporate world with his anti-regulatory views. But he faced criticism on the right over his openness to immigration. Combined with relentless opposition from the labor movement, his nomination proved untenable. It remains to be seen how a new nominee, R. Alexander Acosta, will weather similar scrutiny.
Some unions that have opposed Mr. Trump are finding occasions to thread the needle — like the Communications Workers of America, the union involved in the Momentive strike and a onetime backer of Senator Bernie Sanders’s progressive presidential campaign. It repeatedly denounced Mr. Puzder’s nomination, but in a continuing dispute with AT&T Wireless, it has echoed Mr. Trump’s call not to ship jobs overseas.
Unions in the public and service sectors, on the other hand, lack economic interests that would provide common ground with the new administration, and their membership is increasingly urban, African-American and Hispanic — easily alienated by Mr. Trump’s pronouncements on race and immigration. The Service Employees International Union, a leading service-sector force, has taken a largely oppositional stand.
Many union leaders are at a loss to explain how Richard L. Trumka, the head of the A.F.L.-C.I.O., the nation’s pre-eminent labor federation, will navigate these crosscurrents in the coming months.
Mr. Trumka’s answer for the moment is to proceed gingerly. In an interview, he said that he had a productive meeting with Mr. Trump during the transition, and that the president deserved praise for killing the Trans-Pacific Partnership trade deal. But he has vigorously protested other policies, like Mr. Trump’s immigration restrictions.
“We’re going to call balls and strikes,” he said.