In your fleabag communist cubbyhole
Where the rat shit belongs to the state
You lie on your cot and rot.
While Stalin snores
With his Trotskyite whores
And dreams of the Marxist he's not.
The following paragraph from Deutscher's biography encapsulates the principal reasons that the communist revolutions in Russia and China became corrupted. (2)
Socialist revolution made its first, immense conquests not in the advanced West but in the backward East, in countries where not the industrial workers but the peasants predominated. Its immediate task was not to establish socialism but to initiate 'primitive socialist accumulation'. In the classical Marxist scheme of things revolution was to occur when the productive forces of the old society had so outgrown its property relations as to burst the old social framework; the revolution was to create new property relations and the new framework for fully grown, advanced, and dynamic productive forces. What happened in fact was that the revolution created the most advanced forms of social organization for the most backward of economies; it set up frameworks of social ownership and planning around underdeveloped and archaic productive forces, and partly around a vacuum. The theoretical Marxist conception of the revolution was thereby turned upside down. The new 'productive relations' being above the existing productive forces were also above the understanding of the great majority of the people; and so the revolutionary government defended and developed them against the will of the majority. Bureaucratic despotism took the place of Soviet democracy. The State, far from withering away, assumed unprecedented, ferocious power. The conflict between the Marxist norm and the reality of revolution came to permeate all the thinking and activity of the ruling party. Stalinism sought to overcome the conflict by perverting or discarding the norm. Trotskyism attempted to preserve the norm or to strike a temporary balance between the norm and reality until revolution in the West resolved the conflict and restored harmony between theory and practice. The failures of revolution in the West were epitomized in Trotsky's defeat.
(1) Trotsky always claimed, from personal knowledge, that Stalin had poisoned Lenin.
(2) Deutscher, The Prophet Outcast: Trotsky 1929-1940 (London: Verso, 2003)