Immigration and "the rule of law"

I was listening recently to a very interesting discussion about the history of the American space program, particularly as led by Werner Von Braun , the German rocket engineer who was the most visible public symbol of the manned space program in my childhood. I suddenly realized that one very common theme I hear "immigration control" advocates articulate today is that we need to be strict in our treatment of illegal immigrants because they are "lawbreakers" and the laws must be upheld. Rewind swiftly to the period just after the Second World War when Von Braun and other German scientists and engineers came to the United States and worked in our missile and space programs. The radio discussion on the space program noted that Von Braun was brought to the US completely outside of existing rules and laws for immigration and despite the fact that he had been a principal leader in the German V2 rocket program, a program which used slave labor. To be fair, there was not evidence that he personally had a hand in Nazi atrocities, but Von Braun's history was largely ignored.
As is so often the case, people ignore the realities of American history and action when it suits them. Our government itself has a history of winking at the law when convenient, not just in immigration issues. To say that "the law must be upheld" as a first principle of our collective decisionmaking is hard to defend and this example is just one of many.
Our immigration policy should be rooted in our national best interests-for both the near and long term. Not in using the "law" as a blithe cover for xenophobic sentiments.