The employers who use these workers would probably disagree with you. Fugi is correct on this. 12 million illegal immigrants didn't happen by accident. At some level there was tacit acceptance and the government looked the other way. This has been going on for decades. If it were to suddenly stop, and all these people magically returned from where they came, the agricultural industry would collapse, also with negative effects in construction all the way down to very well to do people paying their house cleaners under the table.
This is how things work, and in alot of ways the various powers that be want to leave it alone.