Just out of college I worked as a bank teller. That job was soul crushing, but this isn’t about that.
I had a coworker about my age. Her husband worked in a manufacturing position. He claimed (but never confirmed) his coworkers were undocumented immigrants. He swore that they didn’t pay taxes and his wife believed him. I tried explaining to her that a few small companies might be able to get away with paying people under the table, but not a large manufacturing business like the one he worked at. I explained payroll taxes to her and how the company would not grossly underreport the number of employees because the first time they got audited they would be shut down, and this place was a major brand. She refused to believe me that those workers paid any taxes, up until one of them came to our branch to open an account. Then she saw his paystub and was really confused that he had taxes withheld, so I explained how IF this man was undocumented, the system had too much to worry about to chase down one guy cashing a check. She was floored by the revelation.
The “illegal immigrants are getting benefits and social security” is one of the oldest and most believed lies from the right.