At this point, it's not even about cheap labor. It's about changing the country to look and act more like central America.
The vast majority of those foreign nationals breaking into our country are very low educated.
"Manual" labor in this country is changing. Not overnight, but it is changing. For example, many pickers in the fields will be replaced by automation. Farmworker vs Robot (from the Wa Compost no less) What will these low skill, low educated people do then? Feed of the taxpayer even more, of course.
As these labor intensive jobs go automated, why is their argument that we still need more than the 10's of millions here illegally already?
How about, implementing a real "guest worker" program. One that's audited by a 3rd party non gov't bureaucracy. They get 6, 9 or 12 month's to be here and work the fields, then go home. They are scanned on the way in, and way out. Anyone overstaying is deported and not eligible to return for 5 years. Any employer who helps them subvert the law, is fined x amount per case and the fines double, etc.
They don't want to fix this. They want to change the country.
Yup. Read the following (from 2007) and let me know if it jibes. Immigration and Usurpation - Real reason why your Senator wants this immigration amnesty bill