Gabe Gabrielsky joined the Socialist Party of America and the Young People’s Socialist League on March 1, 1964, his 21st birthday, the first adult decision of his life and he has been a socialist ever since. Subsequently he was a member (chronologically) of the American Socialist Organizing Committee (ASOC), the Philadelphia Socialist Club, the Independent Socialist Clubs of America (ISCA), the International Socialists (IS), Socialists for Independent Political Action (SIPA), the New America Movement (NAM), the Democratic Socialist Organizing Committee (DSOC), the International Socialist Organization (ISO), the Socialist Party, USA, Solidarity and the Democratic Socialists of America (DSA). Gabe is currently the Treasurer of the Los Angeles Local of the Socialist Party, USA and the branch organizer of the Los Angeles Branch of Solidarity.
Over his working life Gabe was a member of several different labor unions including the United Hat, Cap and Millenary Workers, the Office and Professional Employees International Union (OPEIU), the International Brotherhood of Teamsters (IBT), the International Union of Electrical Workers (IUE), the United Steel Workers Union (USW), , the United Automobile Workers (UAW), the American Federation of Teachers (AFT), the National Education Association (NEA) and UNITE HERE. For a time Gabe was Financial Secretary-Treasurer of IUE Local 416 and a shop steward in UNITE HERE Local 54.
Other issue organizations in which Gabe was active include the Student Peace Union (SPU), the Congress of Racial Equality (CORE), Students for a Democratic Society (SDS), the Peace and Freedom Party, the Citizens Party, Peace Activists East and West Coordinating Committee, the Green Party and Occupy Wall Street. In 2000 Gabe ran for Congress in New Jersey on the Green Party ticket and for the New Jersey State Legislature in 2001 and 2003.