Funny, I live with/amongst a LOT of LEGAL immigrants that obeyed the law.
we don't have the luxury of sweeping through and arresting everyone
If we have the "luxury" of liberating 60M Muslims we were told could never be done, on the opposite side of the earth, why can't we enforce our own laws at home? Oh, that's right, because very few in Washington have the cajones to do so...
Then elect different ones.
And prepare for the labor shortages elsewhere while we go through the grim arithmetic of trying to add enough policemen, secretaries, supervisors, inspectors, busdrivers, jailers, jails, and holding pens to transport 12 million people: but don't make it too permanent, you're going to fire them when they're done. Doesn't sound practical. Let's choose a bit among who we have, and work that way.