OREGON CITY, Ore. (AP) — Thousands of ballots with blurry barcodes that can’t be read by vote-counting machines will delay results by weeks in a key U.S. House race in Oregon’s primary election, a shocking development that is giving a black eye to a vote-by-mail pioneer state with a national reputation as a leader on voter access and equity.

The fiasco affects up to 60,000 ballots, or two-thirds of the roughly 90,000 returned so far in Oregon’s third-largest county. Hundreds of ballots were still coming in under a new law that allows them to be counted as long as they are postmarked by Election Day, and 200 Clackamas County employees were getting a crash course Thursday in vote-counting after being redeployed to address the crisis.

Elections workers must pull the faulty ballots from batches of 125, transfer the voter’s intent to a fresh ballot, then double-check their entries — a painstaking process that could draw the election out until June 13, when Oregon certifies its vote. The workers operate in pairs, one Democrat and one Republican, in two shifts of 11 hours a day.

Voters from both political parties milled about in a narrow room with windows that allowed views of workers opening ballots, transferring votes, reviewing flagged ballots and using the vote-counting machines. They expressed shock at the error and anger at the slow reaction by embattled Elections Clerk Sherry Hall, who has held the elected post for nearly 20 years. By Wednesday night, workers had counted 15,649.

“It blows my mind,” said Ron Smith, a Clackamas County voter. “It’s a little bit questionable. That’s why I’m here. … With all that’s going on, we don’t need extra suspicion. It seems like something like that would have been tested correctly at the beginning of this whole entire process.”

The debacle has stunned Oregon, where all ballots have been cast only by mail for 23 years and lawmakers have consistently pushed to expand voter access through automatic voter registration, expanded deadlines and other measures. It’s also thrown into question a key U.S. House race in a redrawn district that includes a large portion of Clackamas County, which stretches nearly 2,000 square miles (5,180 square kilometers), from Portland’s liberal southern suburbs to rural conservative communities on the flanks of Mount Hood.

In the Democratic primary for Oregon’s 5th Congressional District, seven-term Rep. Kurt Schrader, a moderate, was trailing in the vote behind progressive challenger Jamie McLeod-Skinner. The outcome could have an outsized impact in November, with the possibility that voters could flip the seat for the GOP.

Hall said the problem came to light May 3, when workers put the first ballots returned through the vote-counting machine. About 70 or 80 ballots from each batch of 125 were spit out as unreadable because their barcodes were more faint and slightly blurred. It was too late to print and mail new ballots, she said.

As Election Day approached and ballots stacked up, Hall said she allowed elections workers to take the weekend off because just three people signed up to work Saturday or Sunday.

“We have people mostly between the ages of 70 and 85” and they need rest, she said.

The secretary of state’s office said Hall declined help, saying Clackamas County could handle the situation. Hall told The Associated Press several county workers were assigned to the ballot problem May 11, a week after it surfaced.

Kathy Selvaggio, who lives in the county’s more urban and affluent suburbs, peered through the windows Thursday to watch the vote tally.

“Mail-in voting works, it works well here, but it does undermine my faith in (Hall),” said Selvaggio, who was there as a volunteer for the McLeod-Skinner campaign.

Hall said her department has discussed running test ballots from the printer before they were mailed out, but that her office had used the printer in question for 10 years with no issues.

“There’s lots of other tasks to do,” Hall, who is up for reelection in November, told AP. “I hate the fact that this happened with our ballots. It’s horrible. We need to be building trust with voters and this is not a trustworthy piece, but we are doing what we can.”

It’s not the first time Hall has come under fire in her elections role. In 2012, a temporary election worker was sentenced to 90 days in jail after admitting she tampered with two ballots. In 2014, Hall was criticized for using the phrase “Democrat Party” — a pejorative used by Republicans to demean Democrats — on a primary ballot instead of Democratic Party.

Oregon Secretary of State Shemia Fagan said she is “deeply concerned” by the most recent situation and her office issued a statement Tuesday calling the delay “unacceptable.” But state elections officials said Thursday that they had little authority over local county elections officials.

“The independence of county clerks is an important part of the electoral system and for now we are focused on supporting them,” said agency spokesman Ben Morris.

State law does not require county elections officials to run proof ballots through their machines before mailing them.

Christopher Stout, an associate professor of political science at Oregon State University, said he wouldn’t be surprised to see legislation to change that.

“I think all of these problems, of course, are bad in the short term,” he said. “But in the long term, they’ll lead to improvements, because people will see that those things are problems and they’ll find ways to make it better.”

Former Oregon House Minority Leader Christine Drazan was closely watching results trickle in from across the state Tuesday night. She was eventually declared the winner in the GOP gubernatorial primary the next night.

“I had understood going into election night that Clackamas County knew that this was a challenge,” Drazan said. “So the fact that we were not quite there on election night was just a fact that we had to accept and learn more about how the county was going to respond to that.”

She said voters concerned about the integrity of the process should come watch it in person.

“It should have been addressed earlier with this level of urgency, but it’s pretty rare to have a printing problem like this,” Drazan said.