It sounds just as phony as the claim that it's somehow impossible to deport 12 million criminals. I'm not sure how many are put into prison each year but it must be in the millions so people saying removing 12 million is impossible without any explanation why just reeks of bullshit.
Anyway if the U.S. government just starts imprisoning the criminals who employ illegal immigrants then the illegals would start packing and leaving on their own.
The "essential component of the economy" for theknife is probably his weed supply.
