Roger, the major issue in my mind — as a computer and other security guy — is not what licit uses the ID card could be put to, but the illicit.
First off, the government doesn’t have any better record for maintaining data privately than anyone in the private sector, and arguably worse. A single common ID and the database needed to back it up raises the risk of illicit disclosure a lot.
Second, by having a unified ID card, the ability of a malicious agent to make trouble is much magnified. See, for example, John Brunner’s Shockwave Rider, which has several scenes in which malicious users cause real trouble for real people by hacking national ID databases. A national ID, needed for employment, makes it possible for a rogue individual to make someone else suddenly unemployable; look into the stories about people who have been falsely identified in the NCIC if you aren’t aware of how hard it can be to correct this kind of problem.
Third, and perhaps most worrisome,. is the possibility that this could be used not by a rogue individual, but by a government program with the Common Good (which is always defined as “whatever will pull votes in a contested election”) at heart. For example, can’t you imagine MADD lobbying that anyone who has a DUI should have their ID restricted? Or “deadbeat dad” activists? Or Bill O’Reilly and MSNBC, against “child predators”? This is admittedly a “slippery slope” argument, but given recent history, is it sufficiently unrealistic not to be a concern?
