Otto Strasser (1897-1974) was a German politician, the younger brother of Gregor Strasser. He was ousted from the Nazi Party, by Adolf Hitler, over his left-wing view of socialism in National Socialism. That ouster saved his life, as his somewhat more moderate brother stayed in the Party and was murdered in the 1934 Night of the Long Knives.
While the Strassers were originally Bavarian, they became active in the Munich faction, the Working Association of the North and West. Otto became editor of its publication, as well as a Berlin newsletter, Berliner Arbeiterzeitung.
In April 1930, the non-Nazi trade unions declared as trike, Otto supported them, and Hitler's industrialist supporters told him that they would no longer subsidize the Nazis unless they repudiated the support. Hitler, on 21 May, made a surprise visit to Otto in Berlin, offering to make him Party press chief if he agreed, but threatening to drive him out of the party if he refused. Strasser accused Hitler of wanting to "strangle the social revolution", to which Hitler replied that the social revolution was Marxism: "there are no revolutions except racial revolutions." Hitler, in June, directed Goebbels to drive Otto Strasser from the Party. 
After he left the Party, he formed the Black Front, a socialistic and nationalistic association that was not strongly antisemitic. It had little effect.
- Alan Bullock (1971), Hitler: A Study in Tyranny (Abridged ed.), Harper Perennial, pp. 80-81