And though recent test runs of new computerized voter registration rolls in Indiana and Missouri revealed large numbers of errors, on Election Day reports of problems with the databases were few and isolated. The National Association of Secretaries of States, which represents top election officials from across the country, has said Nov. 7 was generally “a good day.”

But some of the biggest states have not been able to overcome problems with new technology or rules and the lightly trained poll workers who must oversee them. In Ohio, thousands of voters were turned away or forced to file provisional ballots by poll workers puzzled by voter-identification rules. In Pennsylvania, the machines crashed or refused to start, producing many reports of vote-flipping, which means that voters press the button for one candidate but a different candidate’s name appears on the screen.

Perhaps most notoriously, officials in Sarasota County say nearly 18,000 votes may never have been recorded by electronic machines in a Congressional race, even though many voters said they tried to vote.

The recent problems will probably help propel legislation that has stalled for months in Congress mandating that electronic voting machines have a paper trail to better enable recounts. Less clear, experts say, is whether anything will be done to address concerns about the lack of technicians to troubleshoot machines, polling places with too few machines and poorly trained workers, and a system run by partisan election officials who may decide conflicts based on politics rather than policy.

“These types of low-tech problems threaten to disenfranchise just as many people, if not more, but they tend to get less attention,” said Tova Wang, an elections expert with the Century Foundation, a nonpartisan research group in New York. “We still have a long way to go toward fixing the biggest problems with our election system.”

Election workers and experts say the advances in technology have simply overwhelmed many of the people trying to run things on the ground. At a hearing in Denver last week, one focus was on how hard it has become for the poll workers, often retirees getting paid $100 for a 14-hour day, and what it would take to attract younger people who are perhaps more savvy about computers.

“It used to be that you would come in, set up the machines, make a cup of coffee and say hello to your neighbors,” said Sigrid Freese, who has worked at Denver polling places for more than 20 years. Now, she said, the job is complicated and stressful, and “I know a lot of people who said, ‘Never again.’ ”