We have many laws. Some have been around for a long time. Some change over time and still others still exist but are ignored, unenforced or have been forgotten. Perhaps our laws on immigration need examination.But a review of the concept of laws might first be in order.
There are two kinds of laws: those for convenience and those that represent the very essence of what is considered "right" (moral) behavior. Traffic laws are perfect examples of laws of convenience: driving on the left is not morally wrong, but by choosing a side and establishing a law, there is a sense of expectation of behavior that allows all of us to predict others' behavior and render us all a bit safer.
Then we have laws founded on our view of right and wrong. There is a moral foundation. Murder, rape, child molestation, robbery, burglary, trespass...these are all transgressions that have been considered "wrong" morally and our laws make them illegal. Can the morals change...of course, at least on the basis of majority rule. Homosexuality used to be morally wrong. While many religions still hold this, the majority of the population has apparently ruled that is no longer the case, so those laws are disappearing...or at least not being enforced.
What about illegal immigration? Well, what is your opinion on the expectation of privacy, ... or trespass? If you, as a citizen, believe no one has the right to enter your property uninvited )and, if they do, they must be arrested and punished), how can you interpret illegal immigration as other than a trespass? Could we choose to make it OK(moral)? Of course, but then be prepared to give up your right to privacy. Your call.