“Ain’t none of this been working,” he said. He did not vote.

Mr. Albrecht, of the election commission, said other factors contributed to the decline in turnout. This was the first general election under new state laws that required voters to produce an approved photo ID card, and that stiffened the requirements for new voters to prove their residence. This was particularly onerous for the poor, who move often.

Mr. Albrecht said he believed this change had cost several thousand people in the city their vote.

“To me that’s very significant,” he said. “It takes away from the fairness and integrity of the election.”

Although two federal district courts had ruled that the photo ID law discriminated against African-Americans, who disproportionately lack the approved IDs, the law was applied on Election Day after an appeals court stayed one of the decisions. Gov. Scott Walker, a Republican who backed the laws, has said they have no impact on voter participation, and Mr. Albrecht allowed that their effect on Milwaukee’s turnout would not have erased Mr. Trump’s victory in the state.

Perhaps the biggest drags on voter turnout in Milwaukee, as in the rest of the country, were the candidates themselves. To some, it was like having to choose between broccoli and liver.

“I felt cornered,” said Ian Pfeiffer, 25, who works the grill at Jake’s Delicatessen and says he did not vote. “We were stuck between Trump and Hillary. They really left us with no choice.”

Mr. Pfeiffer’s grandmother, an avid supporter of Mrs. Clinton, spent months trying to convince him to vote for her. But he could not get over his revulsion at what he saw as trust issues related to the Clinton Foundation. (Mr. Pfeiffer’s grandfather pushed him toward Mr. Trump, but he found him even less appealing.)

He thought Oprah Winfrey would be a good candidate.

“Hey, would you vote for Oprah Winfrey?” he said in a loud voice to a line of customers.