Before Lenin died, already there were two contenders for his place - the brilliant Leon Trotsky and the cunning Joseph Stalin. The most obvious choice would have been Trotsky, with his quick mind and intelligent speeches. His military skill during the civil war had gained him a lot of support as well. Stalin on the other hand, had been quite an insignificant figure during that time, being only the editor of the propaganda newspaper Pravda. He did, however, make many wise moves, by getting to know the more outstanding people in the party and getting to know them better.
The sick, ailing Lenin knew he was dying soon. After suffering two strokes, it was time to decide on a new leader for the country. He had more faith in Trotsky than in Stalin, describing Stalin's motives as evil, and wanting Trotsky to carry on. He wrote a letter saying that Trotsky should be named as his successor, while Stalin should be gotten rid of.
Stalin naturally hid this letter from the parliament to protect himself, but feared that Trotsky might show it to them at the next meeting, where he would be powerless to stop him. Luckily, Trotsky did not have enough time and Stalin's position was consolidated.
In the meantime, the power struggle was still going on between Trotsky and Stalin. Trotsky was gathering a lot of support with his fluent and brilliant speeches while Stalin was scheming plots to defame his opponents and bring himself to power. Trotsky was succeeding with his seemingly limitless energy and superb oratorical skills, while Stalin's public appearances were strong but not as lasting. Trotsky was skilled in the areas of theories and policies, while Stalin was clearly lacking in these areas. Trotsky seemed to be heading towards an undeniable victory.
However, things started to change. Stalin teamed up with Politburo members Kamenev and Zinoviev. They began to slam Trotsky, picking up all minor faults of his and raking up his past. They emphasized clearly on his Menshevik past and how he was but a newcomer to the party.