On Monday afternoon, a second-shift worker at Harley-Davidson’s powertrain factory in Wisconsin learned President Donald Trump was slated to visit the plant Thursday. Feeling sick to his stomach, he wrote a private Facebook message to a local protest group.

The demonstrators, who call themselves the Milwaukee Coalition Against Trump, contacted Harley-Davidson through Facebook, telling the company they would gather outside the factory to protest the president’s immigration policies. The group organized a call-in campaign, urging activists to flood Harley-Davison and chief executive Matt Levatich with messages, emails and phone calls condemning Trump’s appearance.

On Tuesday night, CNN reported that an unnamed administration official said the trip had been canceled.

During a White House briefing on Wednesday, press secretary Sean Spicer insisted the trip was never set in stone and suggested the planned protest had no bearing on whether Trump would make the appearance. Trump had considered his options, Spicer said, and ultimately decided to invite the Harley-Davidson executives to Washington for lunch.

“Look, it was easier for the executives to come here, considering the week and all of the activity that’s been going on,” Spicer said. “No decision had been made about or announced as to what we were doing.”

Harley-Davidson on Tuesday released a statement, first reported by CNN, saying they “don’t have, nor did we have, a scheduled visit from the President this week at any of our facilities.”

But workers said preparations for the president were well underway. Nearly a week after he signed an executive order barring refugees and citizens of seven predominantly Muslim countries from entering the United States, Trump was quietly scheduled to touch down in the Rust Belt state, which flipped from blue to red in the 2016 election. Secret Service members had cleared rooms in a Hilton hotel in Milwaukee, and agents had already toured the Harley-Davidson facility in Menomonee Falls, said a hotel worker and two factory employees, who asked not to be named because their employers had not authorized them to speak to the media.

The Trump administration did not respond to requests for comment, nor did officials at Harley-Davidson and Hilton hotels.

The White House meeting between Trump and Harley-Davidson, set for noon Thursday, will focus on job creation, Spicer said during the press briefing. Harley-Davidson cut 225 jobs, mostly production positions, last October because of falling motorcycle sales, executives said at the time .

And in Wisconsin, signs of preparation for a presidential visit came to a halt.

An employee at the Hilton City Center in Milwaukee provided to The Post a hotel document that informed staffers Secret Service agents would arrive Monday. The note, which appeared to be sent from a manager of the hotel’s restaurant, said to expect 100 Secret Service members by Wednesday. The employee said no plans had been shared for Thursday.

A “presidential” flight on Feb. 2 from Washington, D.C. to the Milwaukee area, meanwhile, was cancelled Wednesday, according to the National Business Aviation Association’s website, which tracks temporary flight restrictions.

It would have been one of Trump’s first appearances outside of D.C. since he entered the White House. Such trips take a lot of coordination and planning, and it’s possible that even a potential visit from the president would require businesses and the Secret Service to begin preparing days in advance.

Still, Harley-Davidson workers said the messages they received from management sounded definite. One worker, who talked to the Post on condition of anonymity to protect his job, said he saw people who appeared to be Secret Service agents checking out the 92,000-square-foot-grounds on Monday. Then, he said, his boss told him Trump was coming to speak to them Thursday at 2 p.m. The worker said he didn’t want the president in his workplace, but didn’t say anything – he figured most of his colleagues had voted for Trump.

“He’s against everything I stand for,” the worker said. “The way he talks about people, about women and immigrants, is unacceptable.”

Another employee, who asked not to be named because the company had not authorized her to speak to the press, separately caught wind of Trump’s visit on Monday. She said a team leader called her co-workers into a huddle at the start of the second shift and told her the president would stop by.

The employee, who builds engines, almost left the building. She thought Trump took credit for jobs he didn’t save and named as an example Chrysler Fiat, where she said her son is employed. (Earlier this month, Trump had thanked himself for the automaker’s upcoming U.S. expansion, but company said it planned the growth before the election.)

Nobody knew why Trump was coming, she said. Plenty of folks were excited because they liked his talk about keeping manufacturing in the United States. She noticed the place looked cleaner than usual.

Then on Tuesday afternoon, the team leader gave the workers an update. Trump would no longer make the trip to the plant in Waukesha County, home to roughly 44,000 manufacturing jobs.

Wayne Ranick, communications director for the United Steelworkers’ international organization, heard the same account from from some of the union’s Milwaukee members. “We knew he was planning to visit the facility,” Ranick said. “Then we learned that visit had been canceled.”

Gregory Chambers, 32, co-founder of the Milwaukee Coalition Against Trump, said his group’s mission was to publicly oppose Trump’s travel ban, signed last Friday, and discriminatory measures, in general.

“After Harley-Davidson heard we were coming,” he said, “everything was cancelled.”