Not that there is not some amusement in seeing cap agree with his old CFB forum pal JimmStateSkippy, but they have both been selling the line that the protests were somehow about one death.
The one death thing is specious generally, given that any wrongful death done by the State is a reflection of a larger dysfunction. Sacco and Vanzetti were just two guys, but their trial and execution galvanized massive protests and then progress against anti-Italian and anti-immigrant biases. It woke up good people and focused action.
In 1927, protests on their behalf were held in every major city in North America and Europe, as well as in Tokyo, Sydney, Melbourne, São Paulo, Rio de Janeiro, Buenos Aires, Dubai, Montevideo, Johannesburg, and Auckland (I looked it up, yes).