Well, it also demonstrates a complete misunderstanding of an economic system built on the flow of money.
Let's take the ABSURD cost of a massive deportation effort out of the equation. Let's just imagine, as a fantasy, that the Lord God Jehovah issued a command booming from the heavens, and POOF, every undocumented person in America was teleported back to their country of origin. Let's look at the cascade of economic effects there.
Farms? They're fucked. I hope you like your strawberries and lettuce in rotten piles on the dirt, because that's where they'll be. Alternatively, quadruple the price.
Construction? Totally fucked in much of the country. I mean, as a litigator, I'd love it -- the blown deadlines and liquidated damages litigation would keep me going for YEARS.
Restaurants? They're fucked too. Some will close (some have already closed in Austin because they can't find adequate staff at wages that make the business work). At the rest, prices will go up.
Landscaping and janitorial services? Same story.
How many landlords would go broke after losing many of their tenants?
How many stores (think La Michoacana on N. Lamar, and 100 other stores like it in Austin alone) will shut down because of a loss of customers?
How many local restaurants would take a similar hit?
And of course, we're also not including any of the calculations netting out their contribution to the tax base -- remember, when that illegal buys a new pair of boots, those are taxes going into our coffers. When the apartment complex he was in depreciates because it can't fill its beds, that's value off of our tax base. When he isn't working on that construction project, even under a fake SSN, those are SS dollars that aren't going into the coffers.
Immigration is one of those issues that, because of a minor itch, we seem intent on shooting ourselves in the dick economically with a .357. It's just so fucking stupid.