In the last three election cycles, touch-screen machines have become one of the most mysterious and divisive elements in modern electoral politics. In hundreds of instances ... they [have failed] unpredictably, and in extremely strange ways; voters report that their choices flip" from one candidate to another before their eyes; machines crash or begin to count backward; votes simply vanish. Most famously, in the November 2006 Congressional election in Sarasota, Fla., touch-screen machines recorded an 18,000-person "undervote" for a race decided by fewer than 400 votes. The earliest critiques of digital voting booths came from the fringe - disgruntled citizens and ... computer geeks - but the fears have now risen to the highest levels of government. One by one, states are renouncing the use of touch-screen voting machines. California and Florida decided to get rid of their electronic voting machines last spring, and last month, Colorado decertified about half of its touch-screen devices. Also last month, Jennifer Brunner, the Ohio secretary of state, released a report in the wake of the Cuyahoga crashes arguing that touch-screens "may jeopardize the integrity of the voting process." She was so worried she is now forcing Cuyahoga to scrap its touch-screen machines and go back to paper-based voting - before the Ohio primary, scheduled for March 4. Michael Shamos, a computer scientist at Carnegie Mellon University who has examined voting-machine systems for more than 25 years, estimates that about 10 percent of the touch-screen machines "fail" in each election.