Illegal Immigrants and Capitalism

Sounds like a nice ideal, but will it work in reality?

Does the current reality work any better?
Most of the people who have the means to try to come here do so, regardless. I've yet to see any proof of this hidden flux of people who will suddenly pour in from all the countries of the world.

If they're too poor to sustain themselves here they're certainly not going to be able to travel here unless they already have another means by which they could do so.
We could much better use the resources we waste trying to keep them out on making them productive citizens if they can get here - Teaching them our language and developing them for a decent trade.

I've often heard the excuse that if we did this people would come here, get educated on our dime, then go back home and support their original country with skills we gave them, but the hypocrisy of that is that today we're bringing people in on Visa's, training them, educating them and then sending them home when their Visa's expire regardless of whether they want to stay or not. We're criminalizing their presence here when they want to contribute to our society. That's just idiotic.