Writing for the Cato Institute in 1997, author Stephen Moore recalled that during Reagan’s early years in office, “Then-Attorney General William French Smith argued that a perfectly harmless ID card system would be necessary to reduce illegal immigration. A second cabinet member asked: why not tattoo a number on each American’s forearm? According to Martin Anderson, the White House domestic policy adviser at the time, Reagan blurted out ‘My god, that’s the mark of the beast.’ As Anderson wrote, ‘that was the end of the national identification card’ during the Reagan years. -- "Pushing National IDs", The New American, 2007-07-09
Too bad that didn't kill this noxious idea for good. The latest attempt at a National ID is the Real ID act, which was passed in part by using illegal immigration as the excuse, just as in the Reagan story above. It is scheduled to be fully implemented by 2009, but has provoked a significant backlash. For the whole story, see the link above.
The following quote from presidential candidate Ron Paul during the first GOP debate expresses the core philosophical objection to a National ID:
"I am absolutely opposed to a national ID card. This is a total contradiction to what a free society is all about. The purpose of government is to protect the secrecy and privacy of all individuals, not the secrecy of government. We don’t need a National ID card.”