This could all be avoided, say the fans of biometrics, if the entry process were mechanized and based on machine-readable body features such as fingerprints, palmprints or iris scans. The admissible many would zip through the border in a matter of seconds, while the inadmissible few would be routed to secondary inspection for further review, out of the stream of traffic. The logistical challenges seem to be insurmountable, and the risk of error, insupportable. As to logistics, the system would only be effective if nearly everyone on the planet were in the INS's fingerprint database, and it's doubtful that many of us will stand still for that. Those of us secure in our identities, political and otherwise, might not mind too much.
System failure is another reason for caution.
If you can't log on to your computer because you forgot your password, or get into your building because you forgot your cardkey, it's probably a blessing in disguise, at least for a few hours. No machine, and no live border guard, can peer into heart and mind of an intending entrant to determine motive, intent, or purpose with certainty. Most aliens, like most citizens, behave well and want to obey our laws. All rights reserved worldwide.