Question: Did Stalin and Lenin have beef? If so, what about? Did Stalin really betray Lenin's ideas or is that not true? Please support your answers with evidence, quotes with sources, official documents, information on policies they endorsed (separately and/or together), etc. I'm trying to formulate my own position on this.
It’s Trotskyist propaganda. Stalin and Lenin had been allies since they first met in 1905 whereas Trotsky hadn’t even joined the party until 1917, between the two revolutions. Before then, Lenin had frequently called him a traitor and semi-Menshevik. Lenin’s testament, which was written in late 1922 and early 1923 after Lenin had had multiple strokes, included criticism of all the most prominent party members, including Trotsky. Stalin had been elected head of the party in 1921, before Lenin’s first stroke.
In terms of their policies, Lenin and Stalin were both part of the main Bolshevik group, between the ultra-left Trotskyists and rightist Bukharinists. Bukharin had been an ultra-leftist during the civil war but moved to the right during the 1920s. Trotskyists believed the revolution could only succeed if it spread to the most industrialized countries and wanted rapid collectivization. They saw the proletariat as the only revolutionary class and rejected the peasantry. Bukharin strongly supported the NEP and wanted it to continue instead of collectivizing. He believed that even the kulaks (bourgeois farm owners) could lead to socialism. The Trotskyists opposed the self-determination of nations and thought it was a nationalist deviation, while the majority of the party supported it.
If you want more information, Ludo Martens’ book Another View of Stalin has a section on this.