One of the main reasons as to why Stalin came to power and not Trotsky, was that Trotsky did not attend Lenins funeral. This was due to the fact that Trotsky himself was sick and so he took a rest holiday in Sukhumi in the south of Russia. Stalin told Trotsky the wrong date for the funeral, so he thought he would not be able to make it back in time. However really Trotsky could have made it to the funeral but Stalin used this against him. He made Trotsky look like he had committed a cardinal sin, disrespecting Lenins death. Stalin made it look as if Trotsky was sun bathing in Sukhumi and could not be bothered to come to the funeral. This accusation seriously damaged Trotskys political reputation and was ultimately the beginning of Trotskys down fall. With Trotsky not at the funeral, Stalin was able to proclaim himself Lenins disciple saying he would carry on ruling for the sake of their once great leader. One of the ways Stalin paid his respects to Lenin was one of his Political policies. Pay your respects to our once great leader by voting for Stalin. The people started to vote for Stalin in their masses, thinking that they were respecting Lenin but really they were giving Stalin a massive advantage over his political rivals.
Because Trotsky missed Lenins funeral it caused all sorts of problems for Trotsky in the future. He was thought to be insecure. He came across as being unable to stand up for himself in a political fight, he preferred to sort things out in writing. Another apparent insecurity of Trotskys was that he was a Jew and was very conscious of this. Of course Stalin took advantage of this and joined forces with Zinoviev and Kamenev to stop Trotsky becoming a major competitor in the race to the Commissar of the USSR. With the combined force of Stalin, Zinoviev and Kamenevs voters, Trotsky was easily out voted. As well as out voting Trotsky, Zinoviev and Kamenev also questioned his loyalty to the Communist Party, raising his opposition to Lenin. This caused Trotsky to then retaliate by bringing up the lessons of October. The lesson of October happened in 1924, Lenin encouraged it but Zinoviev and Kamenev opposed it With three of them occupied arguing Stalin could advance further in the party without much trouble.
With Trotskys insecurities, he became arrogant and high minded in order to protect himself, so as a result people did not like him. It was said that he was able to match Lenin in his intellect of the Marxist theories; however this made him appear to think himself superior. With the party thinking that he was arrogant, he was not like in the party at all, even though he was very good with the masses. In the end though the population started to see his arrogance and thought too highly of himself, this caused them to stop voting for him. Trotsky was also considered an outsider to the party, because he joined the party in 1917, this was because Trotsky joined the Communist party when he was young and he already wanted respect, which the older party members did not like . One of the only people in the party that did like Trotsky was Lenin who stated in his testament that not only was he distinguished by his outstanding abilities, but also that he was the most capable man in the current Central Committee.
There is no doubt that Stalin was very lucky within the communist party with the timing of Lenins death. If Lenin had not suffered from a stroke, then he would have had the chance to exclude Stalin from the communist party. In Lenins eyes Stalin was considered very rude, aggressive in his methods and dangerous to the people. However Lenin could not expell Stalin orally, so he wrote in it is his testament instead. Comrade Stalin having become the General Secretary has immeasurable power in his hands, and I am not sure he knows how to use that power with sufficient caution. Lenins testament was never read out to the public or the communist party because Stalin, Zinoviev and Kamenev decided it was better that Trotsky was not in power and to keep Stalin on Zinovievs and Kamenevs side. Stalin was very clever with the methods in which he used to progress himself in the party however they were very risky. These risks included misinformation, drastic internal shifts within the communist party and turning party members against each other. Some of the reasons as to why Stalin could take such risks was because he had the control over the communist party and he also had a large wealth of people following him. Due to his pay your respects to the great leader campaign and he understood how to manipulate people. The other party members wanted to join with him and trusted him because he had so many followers and he it appear as if he was one of the most loyal party members of the communist party.
Once Trotsky had stopped fighting with Zinoviev and Kamenev, it only was then that they realized that Stalin had progressed a lot further in the political race to becoming the commissar of the Soviet Union. So in 1926 Trotsky, Zinoviev and Kamenev decided to create a Troika of their own. This would allow then to politically attack Stalin. They believed they had more power than him because there were three of them, however this was not true. Stalin painted them as factionalists because it looked like they had created a separate party just to attack him, which was indeed true. However that is exactly what Stalin omitted to mention that he had done the same with Trotsky making a hypocrite. In 1927 Trotsky was exiled from the party, from there he lived in France, Norway and Mexico. Even though Trotsky was out of Russia he still opposed Stalin until eventually Trotsky was assassinated in 1940 in Mexico by one of Stalins secret police.
With Trotsky gone by 1927 Stalin was almost certainly going to become the commissar of the Soviet Union, which he did in 1929. Some would say that not all of the methods Stalin used to become the Commissar were legal however they did get him to where he wanted to be. They were very aggressive methods and in some cases were considered vicious, but Stalin had the political and tactical mind that helped him to get the top. Besides the methods that Stalin used there is no doubt that luck played a large factor in his rise to becoming the leader of the Soviet Union. If it were not for the fact that Lenin had his stroke at particular time he did and Trotsky was on a rest leave then it would have been a lot harder, nearly impossible for him to become the leader. With Stalin in the chair of power for almost the next 25 years, Russia was about to become a completely different Country.