"So we are going to TRIPLE the worst case impact on society to get rid of guys competing with HS dropouts for jobs installing insulation???!!!"

When people break the law, I expect there to be consequences. Jail, fines, etc. Jail is an excellent disicentive. If someone know that illegally immigrating to this country could land them in jail for a time, would it not encourage them to not break the law? The fiscal break even point, by your numbers, would be 3 not coming here for each one that does. A significant penalty should accomplish this.

I'm totally up for trying it out.