All indications are that near-record voter turnout today will produce long lines and long waits at polling places. We hope that’s the extent of the difficulty that voters encounter. Regardless, Congress needs to revisit the 2002 Help America Vote Act.

After the 2000 Florida election debacle, Congress pumped out $3.15 billion to help states buy new voting equipment, train poll workers and establish statewide voter lists. Despite the help, the 2004 election, too, was plagued by long delays, machine breakdowns and charges of voter disenfranchisement.

This election is going to put monumental stress on the system. Sen. Barack Obama’s (D-Ill.) campaign is hoping for turnout approaching 140 million, while Sen. John McCain’s is expecting 135 million. That’s up from 121 million in 2004, when 60.6 percent of eligible voters cast ballots.

It would take turnout of 140 million to match the all-time record of 65 percent in 1960, according to Curtis Gans, director of the American University Center for the Study of the American Electorate, whose guess is that 2008 will come in at 61 percent to 63 percent.

The Election Day burden has been relieved somewhat by the rapidly spreading custom of early voting — a pattern Gans decries as “an accident waiting to happen.” He argues that early voting doesn’t really increase total turnout and creates the possibility that a late disclosure or incident could leave millions wishing they could change their votes.

Early voting — or no-excuse absentee voting — is now permitted in 33 states, and Oregon’s elections are conducted entirely by mail. This is a state option that is not likely to be revisited until some dramatic incident occurs.

But Gans recommends other changes that would make Election Day more convenient: voting hours like New York state’s — 6 a.m. to 9 p.m. — and funding of adequate numbers of voting machines nationwide.

Congress should consider providing more aid to states if heavy turnout this year results in what appears to be widespread disenfranchisement — because polls close before everyone in line can vote, because large numbers of voters are discouraged by the waits or because of apparent disparities in the ratio of machines to voters.

Every election, we hear charges from Republicans of “voter fraud” and Democratic claims of “voter suppression.” There’s very limited evidence that either is widespread.

But some states require that voters cast provisional ballots when their identity documents don’t exactly match state databases — potentially creating another 2000-like situation in, among other places, Florida again.

And, once again, there’s the paper-trail issue. Thirty-three states now require a paper backup for electronic voting machines, but 17 states and the District of Columbia do not. Congress has never voted on bills requiring backup, but it should.

Given the depth of the country’s economic and foreign challenges, the last thing we need is doubt about the legitimacy of this presidential election or a delay in having it decided. Let’s hope no such thing happens — but Congress should be ready to act to ensure that it doesn’t happen in the future.