Twelve years after the U.S. Supreme Court picked the president amid recount chaos in Florida, there remain plenty of reasons to worry about the integrity of the voting process – from aging touch-screen devices to piles of absentee and provisional ballets whose hand-scrawled contents may decide the race.

One watchdog group, Verified Voting, on Monday cited the possibility of “an election meltdown worse than the Florida 2000 debacle” if a recount is required in Virginia or Pennsylvania, because many votes in those states will be cast on machines that don’t keep a paper record, and thus can’t be recounted (see “The States with the Riskiest Voting Technology”).

And good old paper ballots may still come back to haunt us, especially in the crucial swing state of Ohio, says Charles Stewart, a political scientist and voting technology expert at MIT. Stewart, who was an expert witness in a 2006 case in Sarasota County, Florida, in which 18,000 votes disappeared from an electronic voting system, says disputes over paper ballots loom larger this time.

 “The electronic machines have not been at issue in recent elections beyond a few dispersed problems in programming and calibration. The paper ballots are what I’m worried about,” he said. He explained that in Ohio, if the election is too close to call by Wednesday, “you will have several hundred thousand absentee and provisional ballots yet to be opened. If they are understood to be decisive to the election, challenges to details like name spellings and pen markings on these ballots would certainly arise anew. “That is really the Florida meltdown scenario yet again,” Stewart said.

Pamela Smith, president of Verified Voting, added that the simple age of some electronic voting machines was a concern. “The voting equipment we’re using this time is as much as a decade old.  We’ve heard reports that in some pre-election studies, or in primaries, as much as 25 percent of machines aren’t working.  These are sensitive electronic devices and they get knocked around,” she said.

We’ll be watching the race at Technology Review, keeping you informed throughout the day on issues as they arise—which will become quite dramatic if we have another race like the ones in 2000 and 2004.  In 2000, George W. Bush was certified the winner by 537 votes in Florida, out of six million cast in that state, after the U.S. Supreme Court stopped a recount.  Then, in 2004, Bush beat John Kerry by fewer than 120,000 votes in Ohio, out of 5.6 million cast.

David Dill, a computer scientist and voting technology expert at Stanford, said things have gotten better in some respects, but still with plenty to be concerned about. “Florida and Ohio have gotten a lot better than they used to be, but Florida’s audits are inadequate,” he said.