One of the most important reasons why Stalin won the power struggle is that he used his high positions in the Communist party and the power that came with it to his advantage. Several factors fall under this category. Firstly is how Stalin used his position as General Secretary, as well as jealousies between the leaders and Trotsky’s illness to stage-manage Lenin’s funeral. To the general public, it appeared that Stalin was very close to Lenin, and as a result should become his successor.
In 1925, Trotsky was forced to resign as Commissar for War. This was a potentially powerful position because it meant, if need be, the army would be on Trotsky’s side. Of course, Stalin realised this and how much of a threat it would be to him, and so it was he who persuaded the party to outvote Trotsky. Stalin did this by using his control of the party appointments to his advantage, as well as the 1921 ban on faction and the fears and jealousies within the party.
Two years later, Stalin again used his power as General Secretary and the 1921 ban on factions, this time to manipulate party congress and elections to outvote his opponents. As a result, Trotsky, Zinoviev, Kamenev and other left-wing Communists were expelled from the party; eliminating Stalin’s nearest rivals. Stalin used his party position to remove all Bukharin’s supporters from important positions, and could then put his own supporters in key jobs. This meant that those who could help Stalin were on his side, and he had effectively ended all Bukharin’s chances of becoming leader.
The second most important reasons for Stalin’s ability to win the power struggle are all to do with the fact that he did not propose any new policies.