Putting aside the impossibility of a perfect ID card, will not one that is much more difficult to hack, and expensive to hack, make a real difference. The enemy of the good is often the perfect. I think employers might go to jail, if they don't go throught the simple paces of checking out the better ID, particularly the more high profile ones.
"Putting aside the impossibility of a perfect ID card, will not one that is much more difficult to hack, and expensive to hack, make a real difference."
IMHO, not really. The key is the database, not the card, and the willingness to actually enforce the law. Newt Gingrich made a great point: Your credit card company knows when and where to give approval for credit, cheaply, with a simple plastic card and with some verification. At your workplace, give your driver's license, Soc Sec, etc. and let the INS database verify that you are who you are. They can track real social security numbers, dups, etc. and investigate anything that is suspicious.
The INS could and should track down these things with a verification database. This has been done, proven to work, and only hasnt been implemented because cheap-labor lobby opposes any enforcement.
The picture ID for most Americans is the driver's license, and so long as we forbid it to illegal aliens it should be okay.