You would propose that it is easier to track them if they *never* register than if they do?!
No, just pointing out that your claim of registration will fix the problem is false.
Registration is just one of many things that have to happen. None of the many things that have to happen will work unless they all happen at the same time.
Right now, the US-VIST program registers approximately 99% of every person that uses a visa to enter the country, but to what effect? None. At this time, there is not outbound registration and no way to track then while they are in the US. So at this point, US-VISIT is useless as a registration system.
The same will apply with Bush's proposal. Unless we can track them and register them going outbound, inbound registration is useless.
We have to attack the whole problem, not parts of it. Attacking parts of the immigration problem is a waste of money and manpower.