For Jamie McGregor, a businessman in Springfield, Ohio, speaking favorably about the Haitian immigrants he employs has come to this: death threats, a lockdown at his company and posters around town branding him a traitor for hiring immigrants.

To defend himself and his family, Mr. McGregor has had to violate his own vow to never own a gun.

“I have struggled with the fact that now we’re going to have firearms in our house — like, what the hell?” said Mr. McGregor, who runs McGregor Metal, which makes parts for cars, trucks and tractors.

“And now we’re taking classes, we’re going to shooting ranges, we’re being fitted for handguns,” he said on a recent day, pulling up a photo of his 14-year-old daughter clutching a Glock.

A fifth-generation resident in the small city between Columbus and Dayton, Mr. McGregor was struggling a few years ago to fill positions for machine operators, forklift drivers and quality inspectors, Mr. McGregor, 48, began hiring Haitians who had recently settled in Springfield. They now represent about 10 percent of McGregor Metal’s labor force of 330.

But he has suddenly found himself in the middle of a political firestorm. Former President Donald J. Trump and his running mate, JD Vance, denounced the Haitians in Springfield with false claims that they were stealing and eating pets. The rumors fed growing resentment over rising housing prices, crowded clinics and a town whose character seemed to be changing. Mr. McGregor, who had publicly praised his new employees for their hard work and willingness to learn, became a target.