A computer failed to record changes in the registrations of more than 18,700 Maryland voters, state officials announced over the weekend, meaning that those who want to participate in Tuesday’s primary will have to cast provisional ballots.

Most of the people affected had tried to change their addresses. Some had tried to change their party affiliation.

The announcement late Saturday sparked accusations by Democratic leaders of voter suppression. They said Sunday that they would hold a legislative hearing in July to explore what went wrong.

Election officials said they plan to send emails to 17,600 of the people affected by the computer glitch.

Deputy State Election Administrator Nikki Charlson said those affected can still go to the polling place connected to their new address, but will need to fill out a provisional ballot.

“We always count provisional ballots,” she said.

Election officials said they discovered the problem on Friday, too late to update poll books for the 18,761 voters affected across the state.

The problem began in April 2017, when new software was installed on the Maryland Motor Vehicle Administration’s website and walk-up kiosks. Voters who bought a driver’s license or made other purchases would have their updated information sent to the Board of Elections. But information was not relayed to the Board of Elections for voters who logged on only to change their voter information.

It was not clear Sunday whether the software update in question was initiated by the Maryland State Board of Elections — an independent agency — or by the Motor Vehicle Administration, which is overseen by Republican Gov. Larry Hogan.

State Sen. Joan Carter Conway, the Baltimore Democrat who chairs the Senate committee that oversees election operations, blamed the Hogan administration for the error and expressed concern about the potential impact on close primary races.

“This is not a simple administrative oversight or clerical error,” Conway, chairwoman of the Education, Health & Environmental Affairs Committee, said in a statement. “It is an action by the Hogan administration which will confuse voters, suppress turnout, and disenfranchise thousands of Marylanders.”

Conway said her committee would conduct an inquiry into the problem next month.

The Hogan administration called Conway’s assertion a conspiracy theory.

“This conspiracy theory is so absurd and hateful that it should not be dignified by a response,” Hogan spokeswoman Amelia Chasse said. “Suffice it to say we welcome an inquiry as it will demonstrate this is nothing more than an unfortunate clerical error.”

State Sen. Richard S. Madaleno Jr., a Democratic gubernatorial candidate and one of Hogan’s most prominent critics in Annapolis, called the episode a “failure of the most basic governance.”

“The ability for individuals to register through the Motor Vehicle Administrations website or kiosks was meant to enhance voter participation, not potentially disenfranchise thousands,” he said in a statement.

The Hogan administration reiterated that everyone impacted by the issue can vote on a provisional ballot.

"No eligible voter will be denied the right to vote," Chasse said. "Of course we take everyone's right to vote very seriously. The problem will be remedied well before the general election and is the result of a regrettable software glitch."

Election officials said a computer programming error prevented the address and party changes from being transferred from the MVA to the board.

“The data did not come to us,” Charlson said.

Charlson said voters may go to the state board of elections website at elections.maryland.gov, click on “look up your voter information” and fill out the information to determine if the information is up to date. Those with questions may also call the Board of Elections at 800-222-8683 on Monday and Tuesday.

During early voting, voters who found inaccuracies in their addresses could request a “same-day” address change. That’s not available for Tuesday’s primary.

MVA Administrator Christine Nizer expressed regret over the error. She said in a statement that the agency would work with the elections board “to correct this issue and ensure it does not happen again.”

Charlson said elections officials would “absolutely” have the data updated for November’s general election.

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