I don’t know. If I read it correctly it sounds like a flimsy charge. The 2nd paragraph says the “encouragement” was in giving the illegal immigrant a job. That doesn’t really sound like encouragement though I don’t know what the law actually says or what else may have been done. There were likely other laws broken by all parties here - this one seems really weak based on that paragraph. I admit I didn’t read the entire article.
Knowingly giving the illegal immigrant a job is a crime. The illegal likely committed several crimes as well in accepting the job, relating to falsifying tax forms and falsifying identification. As did the employer. IMO, the 1880 law aside, it's a simple criminal conspiracy.