A Republican-backed voting bill in Ohio could contribute to longer lines at the polls and make it easier to purge voters from the rolls. State lawmakers passed the legislation Wednesday – and there’s likely much worse to come.

The bill itself has voting-rights advocates concerned enough. But it’s almost certain to be just the first step in a broad assault on access to the ballot box expected in the coming weeks from Republicans in Ohio, a pivotal state in presidential elections.

The measure cleared the Ohio House of Representatives by a 60-33 vote Wednesday, with just two Democrats in support. It has already been approved by the Senate and now heads to the desk of Republican Gov. John Kasich, who is expected to sign it. Rob Nichols, a spokesman for Kasich, said Thursday morning that the governor is studying the bill and will announce a decision shortly.

Two key aspects of the bill could restrict voting in the Buckeye State.

First, it makes it easier for Secretary of State Jon Husted to cross-reference Ohio’s voter-registration database with other databases—both within the state and outside it—in order to flag errors, like voters who are deceased or non-citizens, or voters who are registered in multiple states. Voting-rights advocates fear that could allow for flawed purges of voter rolls similar to those conducted recently in Florida, Colorado, and Virginia.

Here’s one way that could happen: The bill could smooth the way for Husted to have Ohio join an effort launched by Kansas Secretary of State Kris Kobach, a former GOP operative and an advocate of restrictive voting laws. Kobach’s project, known as the Kansas Compact, coordinates data from a number of states in order to find voters who are registered in multiple places. The process uses only a voter’s first and last names and his date of birth—a method that, as election law experts have pointed out, is likely to generate a large number of false positives when used on a large scale. Virginia used the system this fall to wrongly purge some voters from the rolls, leading a handful of local election officials to refuse to go along.

“It’s not really clear that the data coming out of that process is really good,” Keesha Gaskins, a senior counsel at the Brennan Center for Justice, said of Kobach’s initiative. The system, she said, “appears to be more of a purge mechanism.”

Kobach’s system aside, the bill would increase the power of Husted—a Republican who’s commitment to protecting voting rights is far from rock-solid –to set the rules on how other databases are used to pare voter rolls. That means the devil will be in the details when Husted issues regulations in the coming weeks.

“People who care about voting rights are really going to have to pay attention” to those rules, Gaskins said.

Second, the bill would reduce the minimum number of election machines that counties are required to have on hand—apparently in response to complaints from smaller counties that have spent money on unneeded machines.

Counties will still be able to order as many machines as they expect to need. But if they miscalculate—perhaps in an effort to save money—they could be left with too few machines and long voter lines.

In fact, that’s a real possibility next year. In January, Ohio lawmakers are expected to pass several more restrictive voting measures. One would put major restraints on the state’s successful absentee ballot system—1.3 million Ohioans voted absentee last year—by requiring sign-off from lawmakers before counties can send absentee ballot applications to voters. Another would end same-day voter registration and make cuts to early voting.

Those bills together are almost tailor-made to produce longer lines on Election Day. That’s where reducing the number of voting machines that counties are required to have could make a big impact in highly populated areas.

“If Cleveland typically sends out [absentee ballot] applications, but the legislature decides not to send them in a particular election cycle, the Board of Election may have already been forced to reduce machines, but could expect a higher Election Day turnout,” Mike Brickner of the American Civil LIberty Union of Ohio explained.

In Ohio, long lines aren’t just a hypothetical problem. In 2004, when President Bush narrowly won the state, and with it the election, some voters in minority and student-heavy areas waited as long as 10 hours to cast a ballot, turning Ohio into the poster-child for voting problems. A Democratic study estimated that around 174,000 people left before voting because of the lines.

That fiasco spurred reforms—among them, efforts to increase early and absentee voting—that have helped the process run more smoothly since then, though there were still reports of long lines in some urban areas last fall. Now, the state is looking to undo that progress.

“Anything that reduces resources at the polls, I think, is severely problematic,” Gaskins said. “When lines are too long, when voters are inconvenienced, it really does undermine the ability of voters to access the polls.”