You are contradicted by the fact that the illegals live an open life and participate extensively in full view of law enforcement and society.
If we slam our borders shut and deport all illegals at this point, it will cause a societal meltdown of epic proportions in Mexico, as well as rampant instability.
With a large portion of the Northern half of South America going Communist, (Oil rich to boot) it would be absolutely dangerous to alienate Mexico from our society. Their most likely solution would be to convert, or buy into Communism.
President Bush has insight that most ignorant purist isolationists refuse to consider, nor would not if it was blatantly obvious. It was the fore mentioned economic instability that brought 1917's Russia to murder their leaders and blindly embrace Lennin's twisted ideology.
We truly live in dangerous times and the majority of conservatives here are ignorant of the obvious outcome.
So do speeders on the highway but it doesn't make it legal. Hookers parade down the open roads. Doesn't make prostitution legal.