Since "Totalitarianism" is a word with deeply emotional baggage, let's see how Wikipedia defines it, and measure it up against Marxism-Leninism and "Stalinism."

Totalitarianism is a political system and a form of government that completely controls the public sphere and the private sphere of society. It is characterized by its prohibition of opposing political parties and its extreme suppression of opposition to the state. In the field of political science, totalitarianism is the extreme form of authoritarianism, where in all political power is held by a dictator. This figure controls the national politics and peoples of the nation with continual propaganda campaigns that are broadcast by state-controlled and state-aligned private mass communications media.[4]

In short, any socialist system that has a unitary form of government, no matter how democratic, is "totalitarian." The additional baggage of propaganda and the use of the word "dictator" are also there to beef this up in scary terms, but at face value any socialist system with a unitary form of government would be totalitarian by this. We will investigate the term dictator later, for now let's continue:

Two versions of the World War II U.S. propaganda poster "Your Lot in a Totalitarian State" depicting a process of compulsory sham election which took place in totalitarian states, the flags of which – Nazi Germany, Fascist Italy[a] and the Soviet Union – are presented below. In the version on the right, produced after Operation Barbarossa, the flag of the Soviet Union (Allied member) is replaced with that of the Empire of Japan[b] (Axis member), which is not always regarded as totalitarian by Western scholars.[1] In regards to the USSR, the label has also received some criticism.[2][3]

Interesting! Wikipedia even acknowledges that labeling the USSR as "totalitarian" is criticized! Let's continue a bit further, for the final paragraphs:

A totalitarian government uses ideology to control most aspects of human life, such as the political economy of the country, the system of education, the arts and sciences, and the private morality of its citizens.[5] In the exercise of power, the difference between a totalitarian government and an authoritarian government is one of degree. Whereas totalitarianism features a charismatic dictator and a fixed worldview, authoritarianism only features a dictator who holds power for the sake of holding power. The authoritarian dictator is supported, either jointly or individually, by a military junta and by the socio-economic elites who are the ruling class of the country.[6]

So, a socialist society with a unified ideology like Marxism-Leninism, and the working class as the rulers of society, is "totalitarian." It's doctored with scary language, but easily applies to any socialist state with a cohesive worldview. Continuing:

The word totalitarian was first used in the early 1920s to describe the Italian Fascist government.[7][8] The term totalitarianism gained wider usage in politics of the interwar period; in the early years of the Cold War, it arose from comparison of the Soviet Union under Joseph Stalin to Nazi Germany under Adolf Hitler as a theoretical concept of Western political science. The term achieved hegemony in explaining the nature of Fascist and Communist states, and later entered the Western historiography of Communism, the Soviet Union and the Russian Revolution; in the 21st century, it became applied to Islamist movements and their governments. The concept of totalitarianism has been challenged and criticized by some historians of Nazi Germany and Stalinist USSR. While the two states are defined as exemplary cases of totalitarianism, these historians argue that the main characteristics of the concept – total control over society, total mobilization of the masses, and a monolithic centralized character of the government – were never achieved by the dictatorships called totalitarian. To support this claim, the historians argue that the political structures of these states were disorganized and chaotic, and that despite the supposed external similarities between Nazism and Stalinism, their internal logic and structure were substantially different. The applicability of the concept to Islamism has also been criticized.[7][9][10]

Now we get to the juice! The word "Totalitarianism" arose to equate the Nazis and the Communists as "twin evils" with "twin devils!" The word itself arose to discredit communism during the cold war! The truth is that the communists uplifted the working class and oppressed the bourgeoisie, while the Nazis uplifted the capitalist class and oppressed the working classes. Superficial similarities are used to equate the entire systems with foundational opposition! This is a part of Double Genocide Theory, a form of Holocaust trivialization. Onto how Wikipedia identifies dictators, to complete this foray:

A dictator is a political leader who possesses absolute power. A dictatorship is defined as a state ruled by a dictator.[1][2] The word originated as the title of a Roman dictator elected by the Roman Senate to rule the republic in times of emergency.[2] Like the terms "tyrant" and "autocrat", dictator came to be used almost exclusively as a non-titular term for oppressive rule.[3] In modern usage, the term dictator is generally used to describe a leader who holds or abuses an extraordinary amount of personal power.

Considering that Wikipedia considers unitary socialist governments, no matter how democratic, to be "totalitarian," they therefore use this to determine the leaders must be "dictators," no matter the democratic process of selection. Moving on:

20th-century leaders typically described as dictators (from left to right and top to bottom): Joseph Stalin of the Soviet Union; Adolf Hitler of Germany; Augusto Pinochet of Chile; Mao Zedong of China; Benito Mussolini of Italy; and Kim Il Sung of North Korea

If it wasn't obvious before, we again return to the "twin evils, twin devils" comparisons meant to directly equate fascism with communism! It cannot be more clear, this is an attempt to equate any existing socialism with fascism. Continuing:

Dictatorships are often characterised by some of the following: suspension of elections and civil liberties; proclamation of a state of emergency; rule by decree; repression of political opponents; not abiding by the procedures of the rule of law; and the existence of a cult of personality centered on the leader. Dictatorships are often one-party or dominant-party states.[4][5] A wide variety of leaders throughout history have been described as dictators.[6]

More baggage and fearmongering onto the word. Given the careful, liberal construction of definitions, it's clear that the only purpose on the Wikipedia entry for "Stalinism" is to contribute to the blanket equating of communism with fascism as twin evils, and liberalism as synonymous with democracy, even though socialist societies with communist governments have been more democratic than liberal democracies, and liberal democracies have far more in common with fascism than fascism with communism.

They'll say all the same things we hear from the most clueless capitalist subjects, day in, day out. They will firehose their recieved propagands into the gap.