The federal government's efforts to create a standardized, secure driver's license that would also serve as a national ID card have hit some significant stumbling blocks.

Chief among them: Eight states have voted in the past year not to participate in the program. Nine others are on the record opposing the proposal. In total, legislation opposing the plan has been introduced in 38 states.

Behind much of the state legislative opposition to the Department of Homeland Security (DHS) plan is Missouri state Rep. Jim Guest, a conservative Republican. His primary concern: REAL ID, as DHS has dubbed the initiative, would not deter terrorists. Instead, he believes, it would be an unprecedented invasion of individual privacy, creating a databank of personal information to which officials on the local, state, and federal levels would have access.

"I love my freedom, I love my country, and we're heading down a road here that would take away many of the things we take for granted," says Representative Guest. "If we had to start carrying a card around – if we lost our freedom not to – I don't think we could ever get that back."

Passed by Congress in 2005 and recommended by the 9/11 Commission, the REAL ID Act requires states to create tamper- and fraud-proof driver's licenses. Each would contain a digital photograph, a digital signature, and a machine-readable bar code. Before issuing a license, a state would have to verify that an individual is a US citizen or has a valid foreign passport and visa. That information would have to be cross-checked against other states', Social Security, immigration, and State Department databases. The intent is to make it much more difficult for a terrorist to get access to a driver's license that could be used to board a plane, as most of the 9/11 hijackers did.

Under the original proposal, the citizens of states who fail to meet the REAL ID standards would not be able to use their state driver's licenses to board planes or enter federal buildings.

Homeland security experts say such a standardized identification system would be helpful in maintaining security.

"This could assure you that people are not using false identifications and boarding planes under false pretenses," says Michael Greenberger, director of the University of Maryland's Center for Health and Homeland Security. "But there are a lot of strong arguments against it. It's become very unpopular, politically."

One reason is the price tag, estimated at $14.6 billion. Congress has so far appropriated only $40 million and twice this summer voted against additional funding. There's also concern about how difficult it would be to implement. Critics question how states could verify the legitimacy of many foreign passports. Conservative libertarians and liberal privacy advocates balk at the requirement that the cards would eventually have an infrared chip containing such personal information as Social Security numbers – machine readable from several feet away. While critics argue that having a central databank could dramatically increase identity theft, DHS contends the secure nature of the ID would decrease it.

The objections raised by states have already prompted DHS to extend the deadline for implementation from the spring of 2008 to 2013.

Last week, Guest and the American Civil Liberties Union (ACLU) sparked more consternation at DHS by claiming it watered down REAL ID requirements so much that it negated the original intent of the program. In a conference call with state officials, including Guest, DHS reportedly said it is considering further extensions. DHS also made it clear that if states don't comply, their citizens could still use passports or go through extended screening to board planes.

"Under repeated and direct questioning about whether or not DHS would enforce penalties against those states that don't comply, Assistant Secretary Richard Barth said, 'No, we are not going to be blocking the citizens of noncompliant states from doing things like flying,'" says Tim Sparapani, the ACLU's senior legislative counsel.

DHS denied it was "watering down" the program and said in statement that the ACLU continues to "spout off erroneous information to confuse and mislead the public."

In a phone conversation later, DHS spokeswoman Laura Keehner insisted, "The bottom line is that we have not backed off anything. We will enforce REAL ID."

But Guest and other state officials say they will fight to repeal the program.