J.C. Thompson works the night shift at Amazon’s warehouse in Bessemer, Ala., a job he started after his work as a hospice chaplain dried up at the beginning of the pandemic.

He says he’s not anti-union but was never a supporter of the effort at the facility. He appreciated the stability of the job and felt the pay and benefits that the company provided were as good as anything a union could negotiate.

His experiences with organizers gave him no reason to change his mind, Thompson said. He received some text messages and phone calls, including one where he says a union supporter suggested workers could make $20 an hour, about $5 more than the starting wage at the facility. But Thompson questioned how that would be possible, and the caller did not answer with specifics, he said. Organizers never tried to make the case for the union away from work, at his home in person.

“The people who were calling, they were weak,” he said.

The loss of the union drive at the United States’ second-largest private employer — the first large-scale attempt at Amazon domestically — has sent reverberations through the world of labor, serving as a reminder of the steep obstacles that activist workers face even in what is shaping up to be the most pro-labor political climate in decades.

Amazon won a decisive 2-to-1 victory during the vote this month after months of organizing efforts by the New York-based Retail, Wholesale and Department Store Union, dashing hopes that a union win could help touch off an organizing renaissance amid the newly labor-friendly climate in Washington.

Now a debate is emerging over whether the RWDSU committed tactical blunders that hurt its ability to reach workers in the face of the company’s relentless anti-union campaign.

Amazon held meetings at which attendance was required and peppered workers with anti-union materials that the union contended veered into false information about requirements to pay dues in a right-to-work state. The union was expected to file claims with the National Labor Relations Board to set aside the results last week. The union said its challenge, which was not immediately made public, would claim Amazon used tactics to mislead and intimidate workers.

Amazon declined to comment. In a blog post Amazon published after its victory, the company wrote, “It’s easy to predict the union will say that Amazon won this election because we intimidated employees, but that’s not true. Our employees heard far more anti-Amazon messages from the union, policymakers, and media outlets than they heard from us.”

(Amazon chief executive Jeff Bezos owns The Washington Post.)

Meanwhile, the fight over the union’s tactics spilled into open view last week on social media, where organizers and worker advocates debated the RWDSU’s track record and strategy, and in left-leaning publications like The Nation, where veteran organizer-turned-scholar Jane McAlevey wrote a blistering critique of what she identified as mistakes made by the union.

Chief among these were the union’s decision to go forward with the election with less than a resounding majority of support, McAlevey wrote. She also pointed to the union’s decision to skip house calls in favor of the phone banking campaign experienced by workers like Thompson. She said organizers should have done “public structure tests,” where a majority of workers demonstrate their support publicly in a petition or poster to show solidarity. And there was too much focus in the news media and elsewhere on the “out-of-state superstars” who joined the effort, like Sen. Bernie Sanders (I-Vt.) and professional athletes.

“Every senior organizer I’ve worked with in the labor movement in the last 20 years saw and shared the same exact concerns that I raised,” McAlevey said in an interview. “They made strategic, tactical mistakes from the beginning straight through to the end.”

Her piece has burned a hole through labor circles, already emotional after what was arguably the most high-profile union campaign in decades. Given the unequal playing field that still exists for workers, McAlevey said she believed the union’s choices also deserved scrutiny — so organizers can learn from mistakes to achieve better results in the future.

Stuart Applebaum, the president of the RWDSU, said he was frustrated by the critique, saying it unfairly cast blame on the union, instead of on Amazon and the country’s weak and outdated labor laws.

“We’ve always known the fight against Amazon was going to be a long one,” he said. “It’s not going to be one election that changes Amazon. But you have to begin somewhere.”

Amazon has denied that it crossed legal lines pushing back on the union.

On Thursday, Bezos acknowledged that the e-commerce giant needs to “do a better job for our employees,” his first public comments on the union drive since the election concluded. He defended Amazon’s record as an employer but wrote that the company needs to commit to improving employee satisfaction as much as the company focuses on providing customer care.

“Despite what we’ve accomplished, it’s clear to me that we need a better vision for our employees’ success,” Bezos wrote in his annual letter to shareholders. He said he intends to include improving working conditions as part of his purview when he relinquishes his chief executive title for a less operational role this summer.

Publicly, many labor organizers are saying the Bessemer loss was still a net gain for workers through the awareness it raised about their plight.

It also provided a high-profile demonstration of what organizers say are typical anti-union tactics, setting the stage for Congress to debate the Pro Act, a robust set of laws already passed by the House — and endorsed by President Biden — that would outlaw many of these tactics.

The Pro Act would stop companies from holding so-called captive audience meetings, mandatory sessions where managers try to dissuade workers from joining, according to labor lawyer Brandon Magner. It would also deprive companies of the legal standing to alter the size of the bargaining unit to try to dilute those in support.

The union drive in Bessemer officially began in November, when a group of workers filed a notice with the NLRB that they wanted to hold an election to create a bargaining unit and be represented by the RWDSU. That initial filing sought to cover 1,500 full-time and part-time workers in that unit.

One of Amazon’s first strategic moves that weakened the union drive was successfully arguing at a NLRB hearing to include nearly 6,000 workers in the unit. That larger figure threatened to dilute union support and came as the company added 500,000 workers globally, growing to 1.3 million employees, since the pandemic began.

Amazon argued at the time that the larger number of workers was the true size of the group of workers that should be allowed to vote.

Some veteran organizers say at least 60 percent of the bargaining unit, but ideally more like 70 percent, should publicly support the union before moving forward with an election, knowing that an aggressive company will always succeed in driving down that number as the election nears.

The RWDSU eventually had more than 3,000 union cards signed, according to Applebaum, but converted only a fraction of those into votes — 738, as well as what the union believes was a majority of 505 contested votes that were never counted because the margin of defeat was so large. The votes against the union tallied 1,798.

One of RWDSU’s lead organizers in Bessemer, Adam Obernauer, acknowledged Amazon “flooded the unit” by inflating the bargaining unit size but said fighting Amazon on that point would have delayed the vote and led to even more attrition among supporters.

“We were still getting a lot of traction on the ground,” Obernauer said. “It’s a calculation you have to make.”

RWDSU’s Applebaum said the new size of the bargaining unit — and relentless turnover in the company’s workforce — posed a major risk for delaying the election.

“If you look at a facility with [such high] turnover in a year, that’s not an option,” he said.

To make its case, the union enlisted prominent politicians such as Sanders and voting rights activist and former Georgia gubernatorial candidate Stacey Abrams to exhort workers to vote yes. It stationed representatives outside the warehouse to engage employees at the end of their shifts.

Amazon, meanwhile, sent some Bessemer workers four to five texts a day, exhorting them not to abandon “the winning team.” It pulled workers off their shifts to mandated anti-union meetings and used fliers posted inside bathroom stalls at the warehouse to sow doubt about the process of paying union dues. Current labor laws allow those tactics.

It petitioned the county to change the timing of the traffic lights, something Amazon said was to improve traffic flow. But the union charged it was a way to speed workers through the intersection near the warehouse and make it harder for organizers to engage them.

The company also asked the U.S. Postal Service to place a mailbox out in front of the warehouse — something the union said may have intimidated or fooled workers into thinking Amazon was running the election. Amazon has argued that the mailbox was installed for the convenience of its employees as they voted in the election. And it said it told workers that only the Postal Service had access to the mailbox.

Emmit Ashford, a 26-year-old pro-union stower, said the company warned workers at meetings that “everything is on the table” and that “you might lose your pay” and benefits if the union were to pass.

The union, on the other hand, couldn’t approach workers except outside the facility, hampering its ability to persuade people who were on the fence.

“It’s hard for the people to get the message across, especially on the union side, because the union doesn’t get to be in the warehouse,” he said.

Robert Muehlenkamp, a former organizing director for the Teamsters, referenced the 1988 book “Confessions of a Union Buster,” saying the union should have been more prepared for what are well-worn tactics.

“Nothing that Amazon did should come as a surprise,” Muehlenkamp said. “They should have known to begin with what an appropriate unit was in that warehouse to begin with.”

Still, other organizers say the deck was always stacked against them.

“When you win, you’re always right. And when you lose, people want to look for reasons why you lost,” said Richard Trumka, the president of the AFL-CIO, which had organizers assisting the RWDSU’s effort.

Under current law, companies don’t face significant financial penalties if they violate workers’ rights to organize. Instead, companies have to rectify the violation — reinstating a worker fired for organizing and offering back pay, for example — after what can be a lengthy legal process for workers and unions.

Employers are accused of violating federal law by workers in 41.5 percent of all union election campaigns, according to a 2019 study of NLRB charges from the left-leaning Economic Policy Institute, and in nearly a third, employers were accused of illegally coercing, threatening or retaliating against workers for their union support. In nearly one-fifth of all elections, employers are accused of illegally firing workers.

Over the last couple of years, about a third of all NLRB charges resulted in settlements between the parties, and about 5 percent resulted in the board issuing a formal complaint.

John Logan, a labor historian at San Francisco State University who is an expert on anti-union tactics and legislation, wrote a lengthy rebuttal to McAlevey’s piece for the self-described socialist journal Against the Current, saying it was based on misconceptions.

“I don’t believe in most cases that unions here would win with smarter, more imaginative and harder working organizers, and that there’s any sort of proven tactics to lead us to victory,” he wrote.

The loss is reminiscent of other high-profile union defeats in red states in recent years — autoworkers at Volkswagen in Tennessee in 2014 and Nissan in Mississippi in 2017. At Amazon, too, nascent efforts to organize U.S. workers have failed, most recently when a small group of equipment maintenance and repair technicians at its Middletown, Del., warehouse voted against forming a union in 2014.

Maria Somma, the organizing director for the United Steelworkers, cited an unsuccessful campaign the union ran for workers at a tire factory in the South a few years ago.

Some 87 percent of a 300 person staff there had signed union cards expressing their support for the union. Organizers had a list of all the employees and their information. But a worker was terminated, others were disciplined, and the company used mandatory meetings — hours every day, Somma alleged — to peel off support for the union, she said. The company did not respond to a request for comment.

“We did all of those things that a good union is supposed to do in the middle of an organizing campaign, and we still lost,” Somma said, although the union did regroup to win a follow-up election held later. “What we need to talk about is the broken legal system and what employers do that makes it really hard for unions to combat.”

Some pro-union workers at the Amazon warehouse agreed, telling The Post that the problem with the effort was not the organizing but the pushback they faced from Amazon — a battle that was complicated by the pandemic.

Darryl Richardson, 51, pointed to tactics like the mailbox, the placement of which he believes could have influenced workers to oppose unionization. Keeping workers apart inside because of social distancing requirements also hampered organizing efforts, he said.

“At Amazon, we couldn’t move about. We couldn’t communicate,” he said.

Obernauer, the RWDSU organizer, acknowledged the pandemic made the union drive more challenging. The inability to hold rallies and meet with workers in their homes took away one of labor’s most effective organizing tools, he said.

“One of the best things during a drive is the feeling of solidarity during meetings, which we couldn’t do during the pandemic,” Obernauer said.