During the Socialist Party's faction fight of the 1930s, Krueger was an active member of the so-called "Militant" faction of young Marxists who sought to turn the SP to the left.
Red Army Faction | Sri Lankan Tamil militant groups | Political faction | political faction | Militant tendency | Whig (British political faction) | Red Faction II | Old Guard faction | Mauritian Militant Movement | Yanan faction | Treaty Faction | The Militant | New Italy (faction) | Militant League for German Culture | Militant faction | Egyptian Communist Party (''ar-Rayat ash-Sha'ab'' faction) | AEC Militant |