Going over articles by my friend Hugh Murray, a veteran of the civil rights movement
(third from the right; New Orleans lunch counter sit-in, September 9, 1960), I noticed in one of them his elaboration upon an inconvenient (for some) fact of Adolf Hitler’s political trajectory.
Rejected by several journals in the late ’90s, Hugh’s “Affirmative Action and the Nazis: Or: Why Liberals Cannot Understand a Holocaust” at last found a home in 2004. Here’s the salient passage (lightly edited; my commentary follows):
Turmoil erupted inside Germany. On New Years 1918-19, the radical Spartacists attempted a coup, but were foiled by soldiers returning from the fronts [of the Great War] who formed into new groups, the Freikorps (free corps). They killed the two Spartacist leaders, Karl Liebknecht and the Jewish Rosa Luxemburg. Elsewhere events went in the opposite direction. In the large southern German province of Bavaria a republic was also proclaimed, led by the Jewish journalist Kurt Eisner, then by the Jewish playwright Ernst Toller, and finally by the Jewish Communist Eugen Leviné . Apparently, one of the supporters of this radical Left regime was a young corporal, recently released, who had been gassed in the trenches toward war’s end, Adolf Hitler (far right, seated, with his Bavarian Reserve Infantry comrades).
The television program The Rise and Fall of Adolf Hitler: [Part] I, The Private Man contains some revealing sequences. [It’s available on YouTube.] I quote from the narration:
With the defeat [of Germany in 1918], revolution broke out across Germany. In Bavaria a revolutionary government was set up. The socialist president Kurt Eisner was shot on the street in [25] February 1919. 
The people turned out to say farewell. Hitler had returned to his Munich regiment, his only foothold, his only home. He was threatened with demobilization and a return to the hostel. A fellow soldier later remembered that Hitler seemed like a stray dog, searching for a new master. In the funeral procession for the Jewish Socialist Eisner was a detachment from Hitler’s regiment wearing both red armbands and black armbands. The film clip shows a lance corporal marching with the officers—Adolf Hitler.
Contrary to his legend about himself, he is wearing the red cloth of the soviets; he sympathizes with the German Socialist Party, a hanger-on with no political home. After the murder of Eisner, Munich was shaken by revolution. The Bolsheviks forced their way into power and for the month of April 1919 set up a Soviet Republic. The Bolsheviks’ leaders demanded loyalty from the soldiers, including Hitler’s regiment. Spokesmen were being elected; Hitler stood as a candidate. With 19 votes he won a seat on the soldier’s council, or soviet, becoming a servant of the forces which shortly after he said he had always hated. In early May troops of the Reich’s central government captured Munich and crushed the soviet dictatorship.
Only then [Murray continued] did Hitler change sides and later cover his past in supporting a Jewish-led soviet government in Bavaria. The 1997 film—produced by ZDF in association with ARTE and the History Channel; written and produced by Guido Knopp and Maurice Philip Remy—shows one who appears to be Hitler in the funeral procession, and displays documents about Hitler’s election to the soldier’s soviet.
So, Adolf Hitler the antisemite attended the funeral of a Jewish socialist and served in its Jewish-led Bavarian soviet. This induces extreme cognitive dissonance in many. Some, psychologizing away what they cannot deny, characterize Hitler’s actions as “opportunistic,” as if his persistent avowal of socialism was insincere. (Or as if opportunism is remarkable in politics.) He “changed sides” but that involved changing the mobs he wanted to lead, not abandoning socialism for free markets.
Hitler was never a Marxist, but he was a socialist who admired Marx’s writings and worked with his Marxist socialist rivals until he could get the upper hand. Why? Because they provided most of the “action” in the years following the Bolshevik Revolution. But he also held that socialism entailed antisemitism and that socialists who didn’t “get” this were misguided.
The attraction was often mutual. George Watson has shown that where leading socialists were not antisemites they were at least eugenicists who favored the extermination of racial “inferiors.” This naturally attracted the attention of National Socialists. The chapter on Hitler in Watson’s The Lost Literature of Socialism is worth the price of the book, but if you’re in a rush, his “Hitler and the Socialist Dream” is freely available online.*
* Also excellent is Bill Flax, “Obama, Hitler and Exploding the Biggest Lie in History,” Forbes, September 1, 2011.