"..undocumented workers coming into the country.."

I've already told you what effect the economic downturn is having on illegal immigration--and why--it's causing fewer to come in, obviously. That's not exactly a mystery.

I thought you already knew.

Why do you insist on treating it as if it is an open question?

If you have nothing more to add, you can always let the topic go. Though I like to see the title of the thread--and I think it's quite significant--it would not be a serious loss if it dropped off the list.