For all the changes in how Ohioans vote, one problem that has remained untouched is provisional balloting. The state relies heavily on provisional ballots, even as experts point to the potential for lawsuits in a close election.

Provisional ballots are used when questions arise on Election Day, voters then casting a ballot that is set aside and counted after it can be checked. But not all provisional ballots are counted. In Ohio, thousands routinely are tossed aside — enough to mean the difference in a close race.

In 2008, some 40,000 out of 207,000 provisional ballots were tossed. Particularly troublesome were 14,000 rejected because they were cast in the wrong precinct, even though voters managed to find the right polling location. Thousands of Ohio voters who had done everything else right on Election Day were disenfranchised for going to the wrong table in a church hall, school gym or other voting location with multiple precincts, a problem most likely in urban areas.

On Monday, U.S. District Court Judge Algenon Marbley sought to correct the situation, ordering Jon Husted, the secretary of state, to tell elections boards to count all provisional ballots cast in the wrong precinct due to poll worker error. Marbley ruled in a suit brought by civil rights groups, the Service Employees International Union and others. The ruling also orders provisional ballots to be counted if rejected on purely technical grounds, such as not completely filling out information on the ballot envelope.

Husted is expected to appeal, arguing the wrong-precinct rule is not an undue burden and applies uniformly to all voters. Marbley correctly sees the larger picture, the state’s rule violating equal protection provisions in the Constitution.

In other words, disenfranchising thousands of voters due to what amounts to a clerical error is an unfair restriction. What’s more, given the state’s history of close elections, provisional ballots could be decisive, with lingering disputes over them further eroding voters’ confidence in the idea that the elections system works for all.