Sincere people ask about so-called "illegal immigrants":Answer: There is no legal way provided for the typical undocumented worker to undertake our jobs in construction, yard work, agriculture, housekeeping, etc. legally.
Eight years ago when my stepson married a European woman, I learned that laws had changed since my 8th grade civics classes! She was by no means an automatic U.S. citizen. Impoverished and illiterate laborers have about as much chance of winning the lottery as they would gaining the "green card" needed to legally do our work.
If you're not current on immigration law, the chart from Reason Magazine provided a cheat sheet on how to become a citizen. Due to it's small size, even if you click to embiggen this graphic, it is still small. You'll want to check out the original on the Reason website, which enlarges nicely. Even better, download it onto your own hard drive for a good look.
Then you can hand a copy to the next person who asks you: "Why don't they enter the U.S. LEGALLY?!?
reprint from Reason Magazine