"From the ACLU's point of view, a biometric national ID card represents a massive privacy invasion," said Christopher Calabrese, the ACLU's legislative counsel for privacy-related issues. "It changes the relationship between the citizens and the state, so things that you used to be able to do as a citizen, like work or travel, suddenly you need this card to do that."
The Senate immigration bill doesn't include a biometric Social Security card, and that isn't likely to change, even as the bill is tweaked in the legislative process.
There's an alternative that the group thinks will be a strong deterrent against hiring undocumented workers, however. Under the bill, an electronic employment verification system, called E-Verify, would be phased in for all businesses within four years.
The same forces -- libertarians and civil rights groups -- will likely push back against mandatory employment verification. But since the system is already in use and mandatory in some states, it's an easier sell.