The U.S. immigration policy is a practical joke. In theory it works, but in practice it does not. Not because it is not practical, but because they are not enforcing the laws as they should. And most importantly, citizens could not care the least. An average American seems to know nothing about documents needed when travelling. If you ask them what a passport is, they do not know. Before someone pounds upon me, I did not say
all citizens. There are a few relatively well-informed or well-travelled citizens.
Why do I mention that? Well, it is for reasons like this that congress passes bills that allow many labourers in (i.e., H-1 visa), who eventually file for and are granted green card. It is also this that allows the government slack on strict immigration laws and enforcing border control.
(Of course this is my opinion. Go ahead and rip it, but don't rip me!

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