Four states are demanding printers that will generate paper receipts voters can see and verify, and more than a dozen other states are weighing the change. But only one - Nevada - expects to have a paper trail in place by the fall elections.
"People are just realizing exactly what we've bought into in some states," said Maryland state Sen. Andrew Harris, a Republican. "The stakes are so high. I don't put it above someone trying to manipulate elections on a grand scale."
Harris wants to fix what many in the computer science world and elsewhere see as a dangerous flaw in the touch-screen machines that will be used in up to 34 states this November.
Their worry? That voters will make one choice, and the machine - through a coding error or a hacker's manipulation - will record it as another. With no one the wiser, election outcomes could be changed.
Many election administrators and voting machine industry representatives say that such fears are misguided, and ignore the rigorous tests and trial runs - from manufacture to Election Day - that protect the vote.
But the doubters are winning support. Harris has proposed that the 16,000 new touch-screen machines that all Maryland voters will use this year be outfitted with a paper ballot printed after a person makes a choice. The voters would then get to see and verify their selection, and the ballot would be secured in case of a recount.
The idea, known as a verified voter paper trail, has been proposed in at least 16 other states as lawmakers have begun responding to months of complaints, letters of protests and security studies that found serious flaws in the ATM-style equipment.
Secretaries of state in California, Missouri and Nevada have gone further and ordered changes. And Illinois passed a law last year requiring a paper trail. Only Nevada, however, will be ready for the fall elections.
"The issue is all about accountability," said Dean Heller, Nevada's GOP secretary of state. "These votes are out there in cyberspace somewhere, and nobody can prove that they exist. The paper trail does."
Because of the state's size, California's change will have the biggest impact, though Democratic Secretary of State Kevin Shelley has given counties until 2006 to add paper ballots.
Florida election officials ruled earlier this year that new touch-screen machines put into place after the 2000 election crisis are exempt from a law that requires manual recounts in close elections - because there is no way to determine voter's intentions from the computer record.
Decisions like that scare some election advocates, sparking their push for a paper trail. (The decision also added fuel to a Florida lawsuit seeking a federal court to order the paper records. No decision has yet been reached).
Stanford University computer scientist David Dill, who runs the Web site VerifiedVoting.org, has collected endorsements from more than 7,000 people for an online petition calling for voting paper trails.
He remains hopeful that the federal government will act, though Congress has gone nearly a year without holding a hearing on several Democrat-authored measures to require a paper trail.
And there is widespread opposition to paper receipts, from election administrators, some computer scientists and even the League of Women Voters.
"It's sending the wrong message to people," said Kay Maxwell, president of the league, a nonpartisan civic organization. "That if you only do this, it settles all the problems. That's not being fair to people, it's not being truthful to people."
The league's argument is that the entire voting system needs funding and attention - voter education, poll worker training, state registration systems. Many of those issues were targeted by the federal Help America Vote Act that has yet to deliver more than a fraction of the $3.9 billion promised to the states.
The group opposes the push for paper trails for electronic voting machines because they say it will not provide the blind, disabled and non-English speakers the same access as other voters.
And election administrators shake their heads about the additional demands a paper trail would create: managing supplies of paper and ink, higher costs for buying and maintaining equipment, and longer lines on Election Day for people with questions, or who want to vote again after seeing their choices.
In Missouri's St. Louis County, printers will add $12 million to the $25 million bill to replace punch cards with touch-screen machines, said Judy Taylor, elections director.
"It's making more of a problem," she said.
By Robert Tanner