An appeals court on Wednesday put on hold an earlier ruling that residents without a photo ID could still vote if they attested to their identity in an affidavit, striking a blow to activists concerned that many in Wisconsin will be blocked from voting.

Advocates for voting rights have had recent legal ­victories with rulings against ­voting-restriction legislation in North Carolina, Texas and Wisconsin.

A federal ruling last month said Wisconsin residents who had trouble obtaining the necessary identification would still be able to vote with an affidavit. But the appeals court on Wednesday said that state lawyers challenging that ruling were likely to be successful.

Wisconsin has battled for years over its voter-ID law, and the latest bout of legal wrangling has left the situation decidedly unclear for voters in November.

In a separate case, a district court judge declared unconstitutional several of Wisconsin’s voting rules and ordered reforms to the process by which voters can obtain IDs from the Division of Moter Vehicles. That decision also is being appealed.

This year more states than ever will require potential voters to show photo ID in order to vote in the election. Here's why this is so controversial. (Monica Akhtar/The Washington Post)

Given the back-and-forth, experts say there remains concern about how much information will trickle down to voters and election administrators. Wisconsin recently made $250,000 available for a public information campaign, although it remains unclear what voters will be told about the rules.

“We know there will be confusion,” said Rick Hasen, a University of California at Irvine professor who specializes in election law.

Dale Ho, director of the Voting Rights Project for the American Civil Liberties Union, said as many as 300,000 registered voters in Wisconsin lack acceptable photo ID, although he acknowledged that not all of them would vote and that some could obtain documentation without much trouble. The ACLU had sued over the law.

As to whether requiring ID could tip the election in favor of the Republicans who support the law, Ho said: “Obviously, the people behind these laws think it can help them. Whether or not it can, from our perspective, it really doesn’t matter. We’re just trying to make sure everyone can vote.”

So, too, is, Anita Johnson, who spends her days stopping passersby at festivals, speaking to church groups and passing out literature with a simple question: “Are you voter-ID ready?”

She is determined to make sure that no voters in her home state of Wisconsin show up to cast a ballot in November only to learn that they will need to produce an identification card they don’t have. The 70-year-old community organizer even drives prospective voters to the DMV to make sure they can navigate the bureaucracy to get the necessary documentation.

“A lot of people still don’t know that you need an ID to vote with,” Johnson said.

[Federal judge rules that Wisconsinites without ID can sign affidavit to vote]

The stakes are high in Wisconsin because November would mark the first time the law would be enforced during a presidential election.

“The numbers are large enough in a close swing state like Wisconsin to make the difference,” said Robert Kraig, the executive director of Citizen Action of Wisconsin, which is among several groups suing in different cases over the law.

In 2012, President Obama beat Mitt Romney by more than 200,000 votes in the state. But other presidential elections in Wisconsin have been closer. In 2004, Democrat John F. Kerry defeated George W. Bush by just 11,384 votes. In 2000, Al Gore beat Bush by 5,708 votes.

In recent days, Democratic nominee Hillary Clinton has opened a significant lead on Republican Donald Trump in Wisconsin. A Marquette University Law School poll of Wisconsin registered voters released Wednesday found that 46 percent supported Clinton, compared with 36 percent who supported Trump. The poll, conducted Aug. 4-7, found Clinton with an even bigger lead over Trump among likely voters: 52 percent to 37 percent.

Rep. Glenn Grothman (R-Wis.) told a local TV station in April that the photo-ID law would “make a little bit of a difference” in pushing his state toward whomever the Republican nominee might be. A former aide to a Republican state senator testified in a trial that GOP lawmakers were excited that voter-ID requirements might help them win.

Hasen said the decision blocking the affidavit-in-lieu-of-ID option for Wisconsin voters will probably be challenged with the full U.S. Court of Appeals for the 7th Circuit, and perhaps even the Supreme Court.

While the legal jousting continues, Johnson said she is still trying to get people their IDs, and bracing for confusion and frustration on Election Day. Even state lawyers — in arguing that the law be kept intact while they appeal — asserted that implementing a process by which voters could use an affidavit to attest to their identity would introduce confusion.

When the law was enforced in the April primary, there were reports of long lines in some places, although the parties have haggled over the reasons for that. Johnson said she observed no significant problems in the primary this month, though she attributed that to low turnout and feared what would happen in November.

“You know what’s going to happen? People will say: ‘I still don't know what I’m going to do. I’m just not going to vote,’ ” Johnson said.

Proponents of the voter-ID requirement, which was signed into law by Gov. Scott Walker (R) in 2011, say that it is a necessary step to prevent fraud and that it — at worst — causes a simple trip to the DMV for those who don’t have an ID. The law requires voters to produce one of several acceptable forms of photo ID when they vote. Lawyers for Wisconsin wrote in one legal filing that the law is “part of a Wisconsin election system that is fundamentally fair, easy-to-navigate, and open to all.” [Appeals court says Texas voter-ID law discriminates against minorities]

Opponents say it is an unnecessary imposition that disproportionately affects poor, minority voters, and its true aim is not to prevent fraud — an imagined problem — but to prevent would-be Democratic voters from casting ballots.

Johnson, a Clinton supporter, said she has driven between 10 and 15 people to the DMV to get IDs, and she has informed hundreds of others of the requirement. Those facing the most serious challenge, she said, are people without birth certificates — which are required to get a Wisconsin state ID.

On a recent weekday, Johnson allowed a Washington Post reporter to tag along as she attempted to get an ID for a homeless man staying in a Milwaukee shelter.

The man, 44-year-old Richard Walker, does not have a birth certificate — although he does have an Illinois ID, a Social Security card and a letter from a Wisconsin food assistance program establishing his residency at the Milwaukee shelter. Wisconsin has a process for confirming his birth information with Illinois, although Walker seemed to need Johnson’s help getting it started.

When DMV clerks twice questioned Walker about whether he had a birth certificate, Johnson interjected, saying Walker wanted to “petition,” a term that the clerks understood to mean he wanted them to ask Illinois to verify his birth information. Walker, an undecided voter, left with a letter saying that if his information checked out, he would be mailed a photo ID. A clerk told him he would leave with no such ID that day. A district judge has since ordered reforms to the process.

Walker may face other obstacles to voting. Records show that he is a convicted felon and registered sex offender, although court records and officials said he does not appear to be on probation or parole. Wisconsin allows convicted felons to vote if they are “off paper,” meaning they have completed any incarceration, probation or supervision that was a part of their sentence. Wisconsin Election Commissions Administrator Michael Haas said that having to register as a sex offender would not itself qualify as being under supervision for voting purposes.

Johnson — who did not know the details of Walker’s criminal past — said his case is atypical, although it did show the difficulty some might face in obtaining an ID.

“He just doesn’t know the terminology,” she said. “They would never suggest the petition process.”

The lawsuit alleged that Wisconsin’s voting regulations are problematic in a host of other ways, and a district judge largely agreed, ordering the state to undo, for example, many restrictions on early voting.

“Wisconsin, in presidential election years, has the second-highest turnout in America,” said Scot Ross, the executive director of One Wisconsin Now, another group involved in the lawsuits. “Why would you want to change that?”