The first reason why Stalin and not Trotsky was able to succeed Lenin was because Stalin had an important position of General Secretary. He used his position as secretary to put his supporters on the Central Committee of the party and dismissed Trotsky’s. This helped him establish control over the party and this lead to him building a powerbase in which he was in control. Having mostly his supporters in the party helped as there were few members in the party who defended Trotsky and made Stalin’s way clear to complete power. So it was Stalin and not Trotsky who became the party leader in 1924 because of his important position where he can put his supporters and get rid of Trotsky’s.
The second reason why Stalin and not Trotsky was able to succeed Lenin was that many communists felt that Stalin was more loyal to the party whilst Trotsky was seen as arrogant. Trotsky had joined the Bolsheviks very late in 1917 and was a member of the Mensheviks, whereas Stalin was there from a very long time. Stalin was the chief mourner at Lenin's funeral. He had told Trotsky the wrong date for Lenin's funeral, and being in the south of Russia, Trotsky believed he couldn't get back for the funeral in time, and so he missed it. Although it was not his fault, it looked to many people that he couldn't be bothered, and he didn't honor Lenin. This made him look bad in front of others. Trotsky also couldn’t be bothered to fit in the group conversations and felt bored. He was once seen reading a novel. So the reason why Stalin became the leader and not Trotsky was because people felt that Stalin was more loyal to the party, while Trotsky was seen as arrogant.
A further reason, why Stalin and not Trotsky was able to succeed Lenin was because Stalin’s policies were more popular. Stalin’s polices included making Russia Strong before spreading communism around the world. Whereas Trotsky believed in permanent revolution. This made