The longest serving socialist in US government was Daniel Hoan, Mayor of Milwaukee (24 years, 1916-1940). He started the first public housing project in the country.
King Gillette, inventor of the safety razor, was a socialist who wrote a book describing his vision of the U.S. population living in a single utopian metropolis/building powered by Niagara Falls. Only 1 in 7 people would need to work, and it would be free of money and thus free of crime.
There was a paramilitary socialist group in Canada in the 1960s that wanted to overthrow their provincial government with an armed revolution. The only peace time use of Canada’s War Measures Act was to stop them. The group was in contact with the KGB, and the top members were exiled to Cuba.
The welfare state was originally a right-wing invention by arch-conservative Otto von Bismarck. Bismarck hated socialism, but he wasn’t an ideologue. He figured out that if you don’t provide a minimum safety net to workers, they will be persuaded by the socialists.
In 1927 the Soviet Union released a film about traveling to Mars where they saved an alien race from capitalism.