The US Real ID Act, which is designed to create an American national ID card, took a hit this week when opponents to the scheme won a victory in the Senate.

During Wednesday's floor debate over a massive immigration bill, Real ID foes managed to preserve an amendment to prohibit the forthcoming identification card from being used for mandatory employment verification, signalling that the political winds have shifted from when the law was overwhelmingly enacted two years ago.

The anti-Real ID amendment is backed by two Montana Democrats, Max Baucus and Jon Tester, who say the digital ID cards represent an unreasonable government intrusion into Americans' private lives. In April, Montana became one of the states that has voted to reject Real ID.

"This was a real victory for Montana and the American people," Tester said, after the Senate vote to kill their amendment failed to muster a majority. The unsuccessful vote to table it was 45-52.

The Real ID Act says that, starting on May 11, 2008, Americans will need a federally-approved ID card to travel on an airplane, open a bank account, collect Social Security payments or take advantage of nearly any government service. States must conduct checks of their citizens' identification papers, and driver's licenses may have to be reissued to comply with Homeland Security requirements. (States that agree in advance to abide by the rules have until 2013 to comply.)

The immigration bill, which is backed by the Bush administration and has drawn the ire of many conservatives, requires employers to demand Real ID cards of new hires starting in 2013. It says that "no driver's licence or state identity card may be accepted if it does not comply with the Real ID Act."

It also would try to siphon off opposition on privacy or federalism grounds from state legislators by offering fat checks -- US$1.5 billion over five years -- with funds coming from the US Treasury.

Baucus' and Tester's amendment deletes the requirement for employer ID verification and says that "no federal funds may be provided" to states to create such a system.

Tim Sparapani, the ACLU's legislative counsel, called the vote a "victory for privacy and a rejection of building an immigration system on a faulty foundation, which was the Real ID Act."

"The way the bill was written," Sparapani said, "it should be seen as a Hail Mary pass to save Real ID from the scrap heap."

A political sea change?
Procedurally speaking, the vote was merely a preliminary one. The Baucus-Tester amendment itself still awaits a vote -- and even if it is glued onto a successful immigration bill or if the immigration bill dies a second time, the underlying Real ID framework and deadlines remain in place.

That framework is estimated to cost US$23.1 billion, according to the Department of Homeland Security, and could include Americans outfitted with radio frequency ID, or RFID, chips on the cards (the idea is being considered but is not final). Personal data that's on the back of the card in a two-dimensional bar code will not be encrypted because of "operational complexity," meaning any business or government agency that scans the information could record it in a database.

Politically speaking, though, Wednesday's vote could be a turning point in the national debate over Real ID. It indicates that a majority of senators are willing to curb the controversial system, which has already led to a kind of grassroots rebellion among the states.

The ACLU, which runs Realnightmare.org, says that 15 states have enacted an anti-Real ID measure, 10 more have had such legislation approved by at least one chamber, and 8 more have had it introduced in the legislature.

Homeland Security officials have defended Real ID as a way to limit illegal immigrants and to thwart terrorists from obtaining driver's licenses. Although some supporters exist in the US Congress, key Democrats have said the law -- enacted with minimal debate as part of an emergency Iraq war spending bill -- needs to be reformed.

Other amendments to the immigration bill could affect any final vote on the legislation. One amendment, backed by senators Max Baucus (D), Charles Grassley (R) and Barack Obama (D), was nixed on Wednesday. It would have rewritten the employment verification system and provided more due process protections for American workers.

CNET News.com's Anne Broache contributed to this report.