The double-marked ballots substantially affected Mr. Gore's showing, a Times analysis of voting data suggests.
As MSNBC's Steve Kornacki pointed out, the voting data backed up Santorum's analysis.
Its research, based on official voting data released by precincts, tells a different picture for dominant Hispanic areas.
The good news for Clinton is that Hispanic turnout is up across all states where early voting data is available.
Stealth programs can be planted in servers and personal computers, and the online transmission of voting data can be intercepted.
It also manipulates voting data, downloads it regularly to other databases, and is designed to ensure security for voting information.
Not every state has tabulated its district-by-district voting data yet, but the liberal-leaning blog Swing State Project has outsourced an amateur tabulation to its readers.
But while Republicans have typically held the advantage in early voting, data available thus far finds Democrats encroaching on their lead.
Hillary Clinton is trailing Barack Obama's performance in the 2012 election, according to early voting data that underlines fears of an "enthusiasm gap" for the Democratic candidate.
An Associated Press analysis of early voting data in North Carolina found that black voters have cast 111,000 fewer ballots than at the same time in 2012.
Clinton's director of state campaigns, Marlon Marshall, drew solace from early voting data which suggests Democratic strongholds are outvoting Republican counties in suburban Milwaukee by two to one.
