I'd like to know with data, (not opinion) the effect of asking all undocumented laborers to leave the US. I heard on PBS recently that the dairy industry is very concerned, they admit to having a high number of undocumented laborers, and cannot compete in the labor market as their product is price-fixed by the government. I suspect the entire produce market is subject to the same concerns.
Is such a question on-topic here, and if so, any advice on sharpening the question for a good set of answers? (From the title, I'm afraid such a question gets closed as 'economic/offtopic'