Voting accuracy advocates and some lawmakers have repeatedly called for printers to be attached to e-voting machines to ensure their accuracy.

Five bills introduced in Congress this year would require voter-verified paper ballots with direct electronic recording (DRE) machines.

But Sen. Trent Lott (R-Miss.), chairman of the Senate Rules and Administration Committee, said that attaching printers to DREs could cause equipment problems. "It seems we're adding a level of complexity," he said.

Sen. Christopher Dodd (D-Conn.), the committee's ranking Democrat, argued that a paper-only system couldn't be used by some disabled people. "By insisting on paper, you're denying people who cannot read because they cannot see," said Dodd, who has introduced a bill that would require a choice of paper, audio or visual verification.

Reassuring Voters

DRE paper trails would reassure voters that ballots are being counted correctly, supporters say. Sen. John Ensign (R-Nev.) said his state used DRE ballots during the 2004 election and they were widely accepted, he said.

"There is no way to build a completely secure electronic system," Ensign said. "All I'm trying to do is make sure the machines are kept honest."

Two computer scientists disagreed over the effectiveness of voter-verified paper-trail ballots. DREs are tested before and after elections, and election officials have better forensic tools to find errors on DREs than on other types of ballots, said Ted Selker, chairman of the CalTech/MIT Voter Technology Project.

David Dill, a computer science professor at Stanford University, said that without verification, voters have no idea of what's going on inside a DRE. "It's not good enough for elections to be accurate; the public has to know that they're accurate," he said.

Los Angeles County has had no problems with DREs since it began using them in 1999, said Conny McCormack, registrar-recorder and county clerk.

"The fact is, the existing DRE systems without the paper trail have a proven track record," she said