"Even though [voter ID laws] will not happen in Maryland, this is a very worrisome development because this is a way of harassing local boards of elections," he said. "And frankly, who knows what these poll-watchers will be doing on Election Day?"
Kelleher said they would follow the state's strict guidelines on poll-watching, speaking only to election judges. "Their job is to be an observer, just to be there to witness how the polls are operated," she said.
Verghese also criticized Election Integrity Maryland and similar groups for not revealing funding sources, saying they have partisan political objectives.
Kelleher says the group is not legally connected to True the Vote, and that its members cover their own expenses and raise money by charging people for poll-watcher training. The group is not required to disclose its funding sources under IRS regulations.
State Republican Chairman Alex X. Mooney said the organization has no ties to the Maryland GOP.
In 2010, the Texas Democratic Party sued the King Street Patriots, alleging that the group was "an unregistered and illegal political committee" and that its actions had harmed the party and the voting public.
"Their principal goal is to undermine certain parts of the vote for Democrats, but more specifically, they target African-American and Latino communities," said Chad Dunn, lawyer for the Texas Democratic Party.
The King Street Patriots challenged the lawsuit, saying that that Texas election law infringed on its constitutional rights to free speech. In March, a Texas judge upheld the election law; the suit continues.
"All we are doing is working to make sure that everyone has the opportunity to participate in a fair election," Engelbrecht said. "We are completely nonpartisan in that initiative."
Rick Hasen, a professor of law and political science at the University of California, Irvine, said "there is no question that voter rolls are a mess in many places." But Hasen, an expert on voting laws, called it "a big leap" to assume that those mistakes are being exploited by people seeking to steal an election.
"If you look at voter registration rolls, in many cases they're terrible," he said. "But they're not terrible because of fraud, they're terrible because of mismanagement and because of lack of budgets to clean them out."
Hasen, who wrote the forthcoming book "The Voting Wars," said it is extremely rare for someone to impersonate another voter at the polls — and that is the only kind of fraud that voter ID laws would prevent. When fraud happens and turns an election, it's usually done with absentee ballots and vote-buying, he said.
Still, Hasen does not agree with estimates that millions of people in the country would be disenfranchised because of voter ID requirements.
Kelleher said her group is not making claims of fraud but pointing out errors that could lead to fraudulent activities. "If that system is working correctly, why are we finding all the dead people?"
Mary Cramer Wagner, Maryland's director of voter registration and petitions, said Election Integrity Maryland has provided "useful and helpful information" to election officials.
But because of state and federal rules designed to protect people's voting rights, election officials "can't just arbitrarily cancel" someone's voter registration, Wagner said.
Maryland is taking part in a multistate initiative called the Electronic Registration Information Center, launched by the Pew Center on the States to help improve the accuracy of voter rolls. The system's data-sharing capabilities are scheduled to be tested for the first time this month, Wagner said.
The Brennan Center supports such technology to reduce errors in voter rolls, said Nic Riley, counsel and fellow with the center's Democracy Program.
"We think those kinds of actions are a much better way of cleaning up and ensuring the accuracy of voter rolls than private-citizen challenges," Riley said.
An earlier version of this article incorrectly stated the name of the center that launched the Electronic Registration Information Center. The Sun regrets the error.