Good thing you used the Polish example...
Solidarity (United States)
Solidarity is a revolutionary multi-tendency socialist organization in the United States, associated with the journal Against the Current. Solidarity is an organizational descendant of the International Socialists, a Third Camp Marxist organization which argued that the Soviet Union was not a "degenerated workers' state" (as orthodox Trotskyists argue) but rather "bureaucratic collectivism," a new and especially repressive class society.[1]
Solidarity describes itself as "a democratic, revolutionary socialist, feminist, anti-racist organization."[2] Its roots are in strains of the Trotskyist tradition but has departed from many aspects of traditional Leninism and Trotskyism. It is more loosely organized than most "democratic centralist" groups, and it does not see itself as the vanguard of the working class or the nucleus of a vanguard. It was formed in 1986 from a fusion of the International Socialists, Workers Power, and Socialist Unity. The former two groups had recently been reunited in a single organization, while the last was an expelled fragment of the Socialist Workers Party (SWP). Solidarity's name was originally in part an homage to Solidarność — an independent labor union in Stalinist Poland which, in Solidarity's view, had challenged the Soviet Union from the left. As of its 2011 convention, Solidarity is a sympathizing organization of the official Fourth International. [3]
I've never heard of the US outfit of that name before. I'll try to use the Polish word "Solidarność" even though it's hell to get those accents marks over the last two letters on this keyboard.