Opinion | The City Sanders and Ocasio-Cortez Would Have Loved to Live In

Unlike Berger, who held deplorable views on race and immigration, Hoan forcefully rejected racism. In 1924, with the Ku Klux Klan in Milwaukee boasting more than 4,000 members, Hoan declared that he would make the city “the hottest place this side of hell” if a K.K.K. member attacked one of his constituents, “whether he be black or white, red or yellow, Jew or Gentile, Catholic or Protestant.”

In 1948, after eight years of Democratic rule, Frank Zeidler, a former county supervisor, became the last socialist to win the mayor’s office. Two years later, Senator Joesph McCarthy of Wisconsin started the Red Scare, but remarkably Zeidler proceeded to win re-election twice during the height of McCarthyism.

Despite hostility from both parties and the press, Zeidler proved to be a highly effective mayor. The business magazine Fortune ran a series on the best-run American cities and ranked Milwaukee second. His appeal lay in his equanimity, and in his empathy, which was forged when Zeidler was a child. “He learned about poverty then,” his daughter, Anita, told me. “He had a job taking leftover newspapers to widowed, single females, who would use them to cover their dirt floors. Sometimes he took food packages, too.” That memory, Ms. Zeidler said, stayed with him throughout his life.

Zeidler’s commitment to his ideals ultimately cost him his political career. In 1955, he was photographed inaugurating an addition to Hillside Terrace, a public housing unit built a few years earlier. He pointedly handed the first sets of keys to two families: one white and one black. That moment contributed to a racist backlash against Zeidler that included violent threats against his family during the 1956 campaign and rumors that Zeidler was using city funds to pay for billboards in the South urging African-Americans to settle in Milwaukee.

“We had a policeman guarding the front and back of the house,” recalled Ms. Zeidler, who died last year. “We went to the F.B.I., but they wouldn’t do anything about it.” Those threats deterred Zeidler from seeking another term in 1960, but he continued battling the real estate industry’s use of blockbusting tactics, which fomented white flight, and never wavered in his commitment to sewer socialism’s egalitarian ideals. “He welcomed any citizen to the city,” Ms. Zeidler said. “He believed every person has equal rights and equal responsibilities.”

Though Zeidler’s decision effectively ended sewer socialism in Milwaukee, Democrats — as they descend on the city next summer to nominate their candidate — should look to sewer socialism’s commitment to economic equality, universalism, organizing, honesty and public investment, regardless of who the nominee is. They might also look, without fear, to the movement’s spirit of idealistic pragmatism, which was captured best by Emil Seidel in his unpublished memoirs.

“Some Eastern smarties called ours a sewer socialism,” Seidel wrote:

Yes, we wanted sewers in the workers’ homes; but we wanted much, oh, so very much more than sewers. We wanted our workers to have pure air; we wanted them to have sunshine; we wanted planned homes; we wanted living wages; we wanted recreation for young and old; we wanted vocational education; we wanted a chance for every human being to be strong and live a life of happiness. And, we wanted everything that was necessary to give them that: playgrounds, parks, lakes, beaches, clean creeks and rivers, swimming and wading pools, social centers, reading rooms, clean fun, music, dance, song and joy for all. That was our Milwaukee Social Democratic movement.