Donald Trump still seems to be learning that there’s a difference between talking tough toward multi-national corporations—like criticizing Apple for outsourcing jobs or threatening to cancel a contract with Boeing—and using his bully pulpit (and soon, the vast powers of the presidency) to single out civilians who cross him. On Wednesday night, Trump took his Twitter assaults to a whole new level when he attacked an Indianapolis union leader who challenged his claim that he had saved 1,100 Carrier jobs from going to Mexico, offering a troubling look at what life may be like for critics of the thin-skinned president.

At the end of last month, Trump and Mike Pence struck a deal with Carrier to prevent hundreds of jobs at two Indiana factories from moving to Mexico. Over the past week, the president-elect has pointed to the agreement as proof that he is already making America “Great Again” and has repeatedly boasted that he saved 1,100 jobs from leaving the United States. “I will tell you that United Technologies and Carrier stepped it up,” he told a crowd of Carrier workers in Indiana last week. “and now they’re keeping—actually the number’s over 1,100 people, which is so great, which is so great.”

But the thing is, the number isn’t actually 1,100 jobs. Under the terms of Trump’s and Pence’s deal, Carrier parent company United Technologies will pocket $7 million in tax credits, in exchange for saving 730 production jobs and 70 salaried positions in Indianapolis. A total of 553 jobs are still going to Mexico and all 700 workers at the Carrier plant in Huntington, Indiana will lose their jobs, WTHR reports.

One union boss, Chuck Jones, decided to speak up, rather than let Trump get away with inflating the numbers.

Jones, the president of United Steelworkers 1999, told The Washington Post in an interview Tuesday that he had hoped Trump would explain to the Carrier workers the actual terms of the deal. “But he got up there and for whatever reason, lied his ass off,” Jones said. “Trump and Pence, they pulled a dog and pony show with the numbers.” Jones continues his criticism of the president-elect in an interview with CNN later Wednesday night. “What nobody is mentioning is that 550 people are losing their jobs,” Jones argued. “First of all, I appreciate Mr. Trump getting involved and saving as many people’s livelihood as he did—so I don’t think that can go without being said. I just wish that he had had the numbers down and he had been upfront with 800 people’s job staying here in Indianapolis because we had a lot of our members, when the word was coming out of 1,100, they thought that they would have a job.”

Trump, who is rarely not monitoring CNN or other news networks, lashed out at Jones on Twitter just minutes later. “Chuck Jones, who is President of United Steelworkers 1999, has done a terrible job representing workers. No wonder companies flee country!” he wrote. An hour later, Trump ranted again: “If United Steelworkers 1999 was any good, they would have kept those jobs in Indiana. Spend more time working-less time talking. Reduce dues.”

Trump’s fury, of course, had the unintended effect of turning Jones into media star and ensuring he remained on the air. “Well first of all, that wasn’t very damn nice, but with Donald Trump saying that, that must mean I am doing a good job,” he told CNN in a follow-up interview, calling Trump’s attacks “pretty low down and low life.” It also meant inciting the wrath of Trump’s supporters, some of whom, he said, had threatened him. “I have been doing this job for 30 years, and you know, I have heard a little bit of everything—people wanting to burn my house down, shoot me, and everything else. So I take that with a grain of salt and I don’t put a lot of faith in that,” he told MSNBC “I am not getting anybody involved . . . I can deal with people that make stupid statements and I will move on.”