Um, ICE in LA WAS rounding them up in buses. They'd go into areas known to have a large illegal population, load them into mini-vans, and take them down to the boarder for deportation. That went on for about a week before the Illegal Rights distinguished mentally-challenged fellows threw a fucking fit.
And it is analogous. Educate yourself on what's going on in CA, Arizona, New Mexico, and Texas. They jump the fence, find someone to give them a fake SS# so they can benefit for the system, but don't pay into it. It's the same as someone walking into your house, eating all your food, and not paying you for it.