This flaw, the group says, exposes Coloradans to voter intimidation and could discourage people from casting their ballots.
But the county clerks deny there are threats to voter privacy and say the allegations put forward by activist Marilyn Marks are not true.
"It's an absolutely fundamental right that we have to a secret ballot," says Marks, the founder and president of Citizen Center, a nonpartisan, nonprofit group that focuses on accountability and transparency in elections. "If we start thinking about what happens if we lose that right...voters can be intimidated. Voters may stay away from polls. Voters can't vote their conscience. That's such an undemocratic proposition. We just cannot let that happen."
Here's the problem, according to Marks: Election staff can trace specific ballots right back to voters through unique barcodes assigned to each ballot.
The example she gives is that a boss who wants employees to vote for a certain candidate could require that all employees hand over their unique barcode numbers from their ballots. The boss could then send those numbers to a friend within the elections office who could confirm whether the employees actually voted the way they said they would.She says she thinks these barcodes exist as an auditing tool, but that it ultimately makes information available to insiders that needs to remain private.
"You are never supposed to be able to do that," she says. "There are longstanding laws to keep you from doing that."
A spokesman for the Secretary of State referred us to the six county clerks also mentioned in the lawsuit, which are Boulder, Chafee, Eagle, Jefferson, Larimer and Mesa.
We were able to reach Eagle County Clerk and Recorder Teak Simonton, who said she couldn't comment in-depth because the lawsuit is ongoing, but she did send us the county clerk's joint motions to dismiss the complaint, one filed in June and another filed at the end of July.
"The counties who are involved with this strongly disagree with her concerns," says Simonton. "It is our assertion...that the serial numbers are not traceable...to a voter."
She says that the process is secure. And another argument in the county clerk's motions is that because the Citizen Center is not alleging that clerks have actually traced ballots or ever threatened to do so, the case is based on "theoretical harms" and thus not legitimate.
Marks says that misses the point.
"They are claiming that there is no harm because no one has ever filed a legal complaint and said...'I've been retaliated again,'" she says. "We are saying it's harm enough when voters know the government can trace their ballot.... It has a chilling effect on the willingness to go vote."
The county clerks also argue that the right to election procedures that make it impossible for a clerk to identify how an individual voted is not a fundamental right protected by the U.S. Constitution.
Marks, though, says that the right to a secret ballot is clearly stated in Colorado's state constitution. She also sent us a document that shows that members of the military who vote from overseas through a fax, for example, have to waive their right to a secret ballot, which she says implies that this is a right that people do have.
Ultimately, she says, the current system could discourage voters, which is her greatest concern. "Will they go to the polls if they know the government can trace their votes?"
More from our Politics archive: Scott Gessler is rewriting rules, weakening disclosure laws, says Colorado Ethics Watch
Follow Sam Levin on Twitter at @SamTLevin. E-mail the author at [email protected].