As I posted earlier, putting all of your eggs into one basket has some critical issues attached to it.
With a multitude of official databases (driver’s license, bank account info, passport, SSN, etc.) you have a systems of checks and balances to help ensure the data retained by each is accurate and honest, despite the multiple opportunities for each database to have information entered incorrectly. Assuming the Reasonable Man Hypothesis for the moment, one would still have to jump through a few hoops if an error was found in one and you had to challenge it to get it corrected. The clerk/guard/security agent stopping you had some level of authority to realize the information was not accurate, provided you with an opportunity to get it corrected as soon as possible, but you were not often denied from proceeding on your way.
A single national ID predisposes a certain level of FUD in the society (effectively perpetrated by the government). That requires everyone to be in the same basket together. With no checks and balances among several trusted databases, what recourse does one person have in correcting the information in a fair and timely manner, when most often, the error is found at a critical moment when access is needed right then and there (at an airport security checkpoint, stopped by a police officer for a traffic violation, etc.)? Sorry but the database says the name is on the terrorist watch list and you cannot board. But, officer, my child is only a month old. You really believe she’s a terrorist?
We already have mindless TSA people refusing to board well-known people, despite their other IDs, well known status and commonsense. Sorry but your name is in our database you you must be a suspect person. WTF?
Besides, what does a national ID protect us from now? Even before computers came along kids were making fake IDs. As IDs became more sophisticated, the tools necessary to create fake IDs came along as well. Now we have the implementation of RFID chips into passports. Yet, it has already been determined the base code for the chips is a UN requirement and details of the requirements are widely known. It has already been demonstrated several times that passports being issued right now can easily be faked and/or cloned using off the shelf hardware, using the already-published UN standards for the RFID chips.
Sure, many kids may not have the resources to make the newer IDs, but we are not talking about a national ID to stop kids from buying beer and tobacco. But is is an unintended consequence of a single national ID. Assuming for the moment that a terrorist group has the time, money and other resources to create fake IDs to meet the RealID Act, they only need to be successful once to accomplish their intended goal. OTOH, the rest of us ordinary innocent folks will have to prove who we are, time and time again, and endure how many stops when the ID information doesn’t add up? Who then is regarded as a potential threat according to the government?