The department cautioned at the time that some people on the list might actually have driver's licenses or other PennDot ID. A person using different first names on voter registration and a driver's license, for instance, would likely turn up as needing ID, said the department's chief spokesman, Ron Ruman.
In fact, an Inquirer review of the state's data suggests there are so many false hits - showing many people without PennDot ID even though they have had it for decades - that the list has little value informing the debate over voter ID, or even identifying who may need help getting credentials to vote.
Former Philadelphia Mayor W. Wilson Goode is on the list as not having PennDot ID. He has had a Pennsylvania driver's license for 50 years.
Goode's son City Councilman W. Wilson Jr. is also on the list. So are four of his Council colleagues - Dennis O'Brien, Brian O'Neill, Maria Quiñones Sánchez, and Marian Tasco. All have licenses.
In addition to the stated problem with people who use different first names on different documents, it appears the state's computers had problems distinguishing names containing spaces, like Mary Ellen, or Van Dyke; names with hyphens, like Olivia Newton-John; and names that computers sometimes spell with spaces, like Mc Dougall.
In Philadelphia alone, more than 10,000 people whose names begin with "Mc" were listed as not having PennDot ID. They included state Supreme Court Justice Seamus P. McCaffery, a driver whose name is spelled Mc Caffery on the city's voter rolls.
Names with apostrophes, like O'Brien and O'Neill, were especially troublesome because PennDot's computer system doesn't use apostrophes, according to David Burgess, a Department of State deputy secretary in charge of computer operations.
The Inquirer tested the state's list by making random calls to registered voters in Philadelphia who were at least 80 years old. The demographic was chosen to gauge the impact of the law on would-be voters who might have the most difficulty getting to PennDot license centers to obtain photo ID.
A team of Inquirer reporters placed calls to 325 of those older voters listed as lacking PennDot ID. Out of 101 people interviewed, 76 said they already had PennDot identification, despite being on the state's list. That's 75 percent.
The Inquirer's sampling technique is not statistically valid, according to experts consulted by the newspaper, because of its focus on a small subset of the 758,000 people on the list - voters 80 and older - and the low response rate, from less than one-third of the voters called.
But it still points to various problems associated with the new law, which was passed by the Republican-controlled legislature in March without a study of its impact, and signed by Corbett with an undocumented claim that 99 percent of voters already had the requisite photo IDs.
The Department of State, whose secretary, Carol Aichele, first offered the 99 percent estimate, now says it has no idea how many voters have acceptable ID.
"We're drowning in numbers here, and we really don't know," Ruman said.
Aichele's initial estimate was based on the 2010 U.S. Census, comparing the number of voting-age state residents, 9.6 million, with the number of PennDot ID-holders who are 18 and older, 9.5 million, Ruman said.
"At the time, that was the best estimate we could come up with," Ruman said. "Do we have faith in it? That's hard to pin down."
On top of the 758,000 initially identified as not having PennDot ID, the state recently sent another batch of data to county election officials - voter-registration information for some 906,000 people who had PennDot identification that expired sometime before Nov. 6, 2011, meaning it won't be valid ID at the polls.
PennDot IDs that have expired within one year of the election Nov. 6 will be accepted.
Opponents of the new voter-ID law testified in Commonwealth Court last week that 10.1 percent of the state's eligible adults, some 957,000 people, do not possess a current, acceptable form of photo ID.
An additional 4.3 percent, some 407,000 people, they testified, might have problems at the polls because the names on their photo IDs are not identical to the names on the voting rolls, leaving it to the discretion of poll workers whether the ID is valid.
The numbers were based on a survey of 1,285 randomly selected Pennsylvanians directed by Matt A. Barreto, an expert on voter-identification laws at the University of Washington.
Close to one million believe they have valid photo ID but do not, the study found.
At first blush, any signs that the state overcounted the number of voters without PennDot ID might help the Corbett administration's contention that its new photo-ID requirements are reasonable.
But the mistakes the administration made in trying to compare the two lists of voters and PennDot licensees are so basic they cast doubt on any conclusions.
While the computer work was being done, Philadelphia's top election official, City Commission Chairwoman Stephanie Singer, tried to connect with PennDot officials, but Aichele's office canceled a phone conference.
"We want to make sure that when we get something, it will be something we can rely on," Singer said at the time.
The Department of State now says its exercise wasn't aimed at providing an accurate list of those without voter ID, but rather, at developing a mailing list to notify those who might have problems with the requirements.
"We felt we wanted to err on the side of caution, to send letters to some people who probably have IDs, rather than take a chance of missing folks," Burgess said. "We would rather spend a few extra dollars and send a few extra letters."
The Corbett administration has allocated $5 million in this year's state budget to pay expenses tied to the new voter-ID requirements.
The City of Philadelphia, without any money allocated for voter ID, had hoped to get a reliable base for its own outreach efforts. "We still don't have it," Deputy City Commissioner Jorge Santana said.
Even if 80 percent or 90 percent of the people on the state list actually have PennDot ID, that would still leave thousands of registered voters without it, critics point out.
Another possibility, attractive to those who believe there's been massive vote fraud in Philadelphia and elsewhere, is that virtually all real people already have photo ID cards and that the new law will weed out thousands of fictional people whose names have been used to cast illegal votes.
Only one possible voter-impersonation case has been identified in the city in recent years: the 1990 registration of one Joseph Cheeseboro, using a South Philadelphia address that later became a vacant lot, and the subsequent 2003 registration of a Joseph J. Cheeseborough, with a convenience-store address.
After a state Republican aide, Joseph DeFelice, brought the Cheeseboro situation to city commissioners' attention early this year, neither Cheeseboro version cast ballots in the 2012 primary. But one Cheeseboro or the other has voted in eight elections since 2007, when both voted in the primary and general.
The name Joseph Cheeseboro, but not Cheeseborough, appears on the state list of voters without PennDot ID - along with DeFelice, who said he's had a Pennsylvania license for years.
Contact Bob Warner at 215-854-5885 or firstname.lastname@example.org.