Attorneys representing the state and a civil rights group dueled over whether errors from punch-card ballots are the fault of the machines or the voters themselves during the first trial to challenge the use of punch cards since the 2000 presidential election.

Dana Walch, director of election reform at the Ohio secretary of state's office, testified Monday that state studies show voters make most errors that lead to punch-card votes not being counted, such as picking more candidates than allowed in a contest.

But the American Civil Liberties Union (search) suit is the first of its kind in the nation, voting experts say. Lawsuits filed against several other states have been settled with agreements that punch-card ballots will be replaced.

In Ohio, the ballots are used in 69 of 88 counties, representing nearly 73 percent of registered voters. In the 2000 presidential election, nearly 94,000 Ohioans had their ballots rejected.

ACLU of Ohio lawyer Paul Mokey noted that Ohio's Hamilton County, which had aging punch-card machines in the 2000 election, discounted 2,916 ballots with more than one candidate selected for president, yet Franklin County, which had touch-screen electronic voting, reported no such ballots.

"In a close election such as that is predicted in Ohio this fall, those 2,916 votes could make the difference," Mokey said.

Punch-card balloting gained notoriety during the 2000 presidential election in Florida, where problems with the ballots — such as hanging chads — led to legal wrangling and recounts, until George W. Bush was declared the winner of the state by just 537 votes.

Ohio plans to replace punch-card systems by 2005 with machines that alert voters they made a mistake. The electronic voting systems were supposed to be in place statewide by November, but the $133 million plan has been stalled because of security questions.

"We needed to ensure the public that the voting equipment that we were about to spend considerable taxpayer funds on was secure," Walch testified in the opening day of the trial, which was scheduled to resume Tuesday in U.S. District Court.

Even if punch-card systems can't be replaced before November, the ACLU still wants the judge to rule them unconstitutional. Judge David D. Dowd agreed to hold more hearings to determine possible remedies if he rules in the ACLU's favor.