The idea that if we deport 12,000,000 illegals ( who will take probably 12,000,000 more dependents and spouses with them) and unemployed Americans will then take up roofing, masonry, landscaping, farming, childcare, cleaning, etc. is wishful thinking. If they were willing and able to do so they would already be working.
But an open border is unacceptable as well. Maybe after the election Congress will suddenly do it's job and pass a new immigration policy. That too is probably wishful thinking.
As an aside, I just retired a year and a half ago. It is amazing to me how many men I see during the day just wandering around doing basically nothing. No wonder there is crime with so many seemingly with nothing to do.