To make “working class power” the shorthand definition of 21st socialism reveals a bit of a tin ear, given the the democratic failures and authoritarian excesses of “working class power” in the socialist countries in the 20th century. A broader definition should include socialism’s vision, values, problem solving capacity, and, especially, its democratic character, while, at the same time, making abundantly clear that power in any form will be accountable to and checked by a robustly democratic polity, culture, media, and popular institutions.
Furthermore, power in a socialist society wouldn’t be the property, constitutionally or otherwise, of any one party. Socialism should diffuse power, not centralize it into the hands of any single entity.