Like it or not, immigration (legal or otherwise) and travel are part of life. The U.S., being a rich country with a short memory, tends to forget that public health requires constant vigilence... and is one of those areas where even conservative libertarians have to admit it's the State's responsiblity to provide for it.
How clueless are you?
Nobody argues with legal immigration so why do you preface your remarks with, "like it or not?" The U.S. didn't forget that public health requires constant vigilance, it has chosen to ignore our public health laws in deference to the PC crowd.