You would need to study the Life of Lenin and his work in the RSDLP to see how he struggled to democratise the movement and keep it democratic. The fight against the puppet Duma set up by the Czar was a totally democratic process and the basis of the revolution. It should be remembered that there were two revolutions in 1917. The February revolution deposed the Czar and installed Kerensky who tried to use the old puppet duma of the czar, which was clearly not democratic and was filled with old Czarist officers. The Bolsheviks had little or no influence during that time. The Bolsheviks won their support among workers and soldiers through an entirely open and democratic process
The Latin word Democracy means will of the people and the will of the people cannot be exercised on the basis of a single vote once in four or five years, from a preselected bunch of monkeys. That is demockery. The limitations of such a system for expressing the will of the people can be seen in the current situation in Egypt. A democratically elected president tried to use his period of rule to install himself and his cronies as permanent rulers. The army has stepped in to remove him and will try to hold new elections which rules Morsi and the Muslim Brotherhood out of the equation. That will not be democratic either. Hitler gained power in precisely the same way, through the ballot box in a parliamentary election to the Reichstag. After election the machinations could begin in earnest and he was helped immensely by army officers, not least by Hindenburgh.
For true democracy it is necessary to establish a bottom up structure whereby all officials are elected at local level and can only remain in their positions as long as they have the support of those who elected them. They should be subject to short term recall and lose their position in 24 hours if necessary. This applies to all officials. At District level the officials are delegates elected by the locals. These delegates form a District Committee (DC) and from among these members the executive committee will be elected. This in a nutshell is Democratic Centralism. It is essential that those elected to positions of authority have proved themselves by their work at local level and who continue to demonstrate good work at their local.
Delegates to the Annual National Congress are sent from each local and at that congress the central committee will be elected. The process usually followed for electing the Central Committee (CC) is for the outgoing CC to present a slate, of full CC members and alternates, in order to maintain continuity in the work of government. The slate can be rejected any number of times, until a slate which suits the general membership delegates can be formed. All members of the CC are subject to short term, 24 hour recall. Once the CC is elected, their leadership is followed in a disciplined manner unless and until a dissenter can accumulate support from at least two locals, which then starts discussion at DC level. Two DCs presenting disagreement with the CC is sufficient to force a recall Congress if the CC does not act in a way which settles the matter to the satisfaction of the disputing DCs. This prevents spurious disruption, but ensures that all genuine grievances are taken seriously. The CC will not wish to go through the tortuous process of re-election, so it will have to act.
The alternate members can be present at the CC meetings, so they can learn the ropes participate in discussions and follow developments, though they cannot vote. This is their preparation for being considered for the slate at a future congress. Alongside the CC, a control commission is elected. These delegates do not have any political powers, but are able to investigate all and any irregularities in procedure. They also audit the books. Since they have no axe to grind, they will exercise their powers to ensure the organisation runs properly.
One of the basic problems which can arise is stable groups on the CC. This is to be avoided at all costs and where such a group arises, steps must be taken to expose it and isolate it. Stable groups are poison to any democratic process - friends voting for each others ideas is not the way forward.
Lenin and Trotsky always said that Democratic Centralism was not written in stone and was not necessarily the perfect system. Ways should always be looked into to refine and hone the process. Different times and situations might throw up conditions under which Democratic Centralism would need to work in a different manner and it was in response to the civil war, sparked by disaffected rich landowning peasants and and ex-Czarist officers, that full democracy had to be suspended. The USSR had to operate under a war council with Lenin at the head and Trotsky as his leading assistant. The CC remained in place and democracy was continued through the party apparatus. This was later learned to be a mistake, because Stalin was made General Secretary and he began stirring up trouble, because of his abrasive manner when dealing with peoples who needed to be handled sensitively. Lenin saw this and warned Trotsky that he considered Stalin a disaster. "This cook will only create spicy meals." Was Lenin's verdict.
Immediately after the war Lenin and Trotsky embarked on the process of restoring democracy to the USSR and they knew that meant a fight with Stalin. They agreed to try and get Stalin replaced, but by 1923 he was too powerful, having drawn to his support all those army officers who no longer had a role, now the war had been won. He drew also those who liked power and privilege. Economic isolation of the USSR was taking it's toll and hunger and want were now the most pressing problems for the young socialist state. Measures had to be put into effect for properly distributing food and rebuilding production, but yet again Stalin took the heavy handed approach and at that particular time, the simplistic answers were more appealing than the detailed and complex propositions of Lenin and Trotsky. Stalin strengthened his position with the help of a cabal and Lenin and Trotsky became Isolated. Lenin died in 1924 and it is widely believed that Stalin had him poisoned. Trotsky was isolated and weaker members of the CC formed a stable group around Stalin, making it impossible for Trotsky to make a successful challenge. Those CC members would pay dearly for that error.
Trotsky's fight with Stalin was one of Democracy Vs dictatorship and it was for this that Stalin reserved a special hatred for him. Stalin did not have the confidence in the people to be a democrat, whereas Lenin and Trotsky thrived on putting their ideas to the vote.
When Trotsky finally broke with the Third International, he formed the Fourth International and the founding document at it's first congress, warned against the creation of a one party state - under any conditions.
Stalin was a peasant, a bank robber who gained popularity among the Bolsheviks and among Bolshevik workers and soldiers, because of the way he boosted the party's funds. A man of action, not an armchair strategist. He was poorly educated and did not have the head for the simplest of political tactics. He would bluster his way through problems, in much the same manner as some past British Trade Union leaders would. This led to mistakes, the effects of which required extreme manipulation to overcome. Mistakes were never corrected and principals lasted only as long as they were expedient. In short, Stalin had no principals and never owned to an error. Best example of that is in the way he eulogised Lenin, cannonised him, yet trampled on everything he stood for and the way in which he destroyed the Chinese revolution by insisting the Communist Party fuse with the Kuomintang. This catastrophic blunder, which cost the lives of a million or more communists at the hands of Chiang Kia Shek was compounded five years later when he ordered the Communist party to fuse with the Nazi party and destroy the SPD, during his "Third Period" madness. The headsman's axe fell on the neck of many good communist youth. The Spanish revolution was deliberately destroyed by Stalin. By the mid-'30s he realised that the thing which would most easily destroy him would be a successful revolution elsewhere. Trotsky would be proved right.
Power turned Stalin into a monster and his ghastly machinations turned the USSR from a democratic socialist state into almost the mirror image of the Nazi terror. It was complete in very detail, with Jackboots, whips, barbed wire, concentration camps and mass executions. It was a long gradual process, which began in 1927 when Stalin was freed from all criticism with the exile of the hated Trotsky and by 1934 it was complete.