The Milwaukee Election Commission will seek a formal U.S. Postal Service investigation into what happened to absentee ballots that did not reach Milwaukee voters, commission Executive Director Neil Albrecht said Wednesday.

Albrecht said the commission wanted the investigation to be centered around "absentee ballots that were issued and mailed by the City of Milwaukee around the March 22nd and 23rd period."

He said the city saw a pattern of calls from voters whose ballots had been issued on March 22 and March 23 but never reached them. But he also said the majority of ballots issued on those dates did reach voters.

"The pattern that we saw in terms of a volume of voters — and I can't give an exact percentage — calling in and saying that they had not received their ballots really drew our attention to those two days," Albrecht said during a virtual news conference Wednesday afternoon.

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When the city learned of the issue with ballots not being delivered to voters, officials immediately began re-issuing ballots to voters who had made a request over that period of time but had not gotten their ballots, he said.

“I try to keep all of this in perspective, which is to say, Wisconsin is not a state presently set up to administer a by-mail absentee voting election and that the infrastructure that is in place was across the board tested by the volume of absentee votes,” Albre said, referring to the MyVote website, clerks trying to process requests and the Postal Service trying to deliver the ballots.

He said the city is looking to the state for guidance on which completed absentee ballots received by his office can and cannot be counted because many absentee ballots don't have postmarks.

The U.S. Supreme Court on Monday ruled that ballots had to be returned to clerks by Tuesday or postmarked by then to be counted.

For municipalities that use postage meters for sending out their absentee ballots, a majority of their absentee ballots don’t have postmarks, he said.

Albrecht anticipated the postmark issue would become particularly problematic for ballots returned Wednesday that were clearly sent by the deadline but that don’t have a postmark. He wasn’t sure whether those ballots would be counted or if the U.S. Supreme Court’s ruling on the postmark will be interpreted literally, disqualifying ballots without postmarks on or by April 7.

USPS couldn't immediately be reached for an interview Wednesday afternoon.

Contact Mary Spicuzza at (414) 224-2324 or mary.spicuzza@jrn.com. Follow her on Twitter at @MSpicuzzaMJS.

Contact Alison Dirr at 414-224-2383 or adirr@jrn.com. Follow her on Twitter @AlisonDirr.