You throw out so many straw men in this article. First, I know of no policy that says we need to deport 12 or 20 million illegal aliens. Most are for just enforcing the current laws. If employment laws were effectively enforced, those in this country illegally will leave due to not being able to find a job. On that point, it should be that no one in this country illegally should get any sort of welfare. They won't stay if they can't provide for themselves.
Your point about the founders wanting a thriving immigrant base is accurate, but they also saw the value in the rule of law. I'm sure if you were to look at it for real, you would see that none of them would have supported an invasion from foreign nationals..