A communist party is a political party that advocates the application of the social and economic principles of communism through state policy. The name was first in the title of the 1848 tract Manifesto of the Communist Party by Karl Marx and Friedrich Engels. A communist party is the vanguard party of the working class (proletariat), whether ruling or non-ruling. As a ruling party, the communist party exercises power in the name of the dictatorship of the proletariat. The idea of communist party dictatorship was heavily influenced by Vladimir Lenin's writings about the role of the revolutionary party in the first two decades of the twentieth century when Russian social democracy divided into Bolshevik (meaning "of the majority") and Menshevik (meaning "of the minority") factions. Lenin, leader of the Bolsheviks, argued that a revolutionary party should be a small vanguard party with a centralized political command and a strict cadre policy emphasizing subservience to the party's decisions; the Menshevik faction members like Trotsky, in contrast, argued that the party should not neglect the important role to be played by the masses in a communist revolution. The Bolshevik party, which eventually became the Communist Party of the Soviet Union, took power in Russia after the October Revolution in 1917. With the creation of the Communist International, the concept of party building was copied by emerging Communist parties worldwide. The Comintern required every one of its members to call themselves communist. They were subsequently known as Leninist or, later, Marxist-Leninist parties. The doctrine of Leninism which was popularized by Joseph Stalin in 1924 in the handbook, Problems of Leninism.
The Communist Party USA is also banned in the United States under the Communist Control Act, however the Act was never enforced and the Party still exists today. Some U.S. states also have their own laws banning the CPUSA; likewise none of those laws have ever been enforced.
As the membership of a Communist party was to be limited to active cadres in Lenin's theory, there was a need for networks of separate organizations to mobilize mass support for the party. Typically, Communist parties have built up various front organizations whose membership is often open to non-Communists. In many countries the single most important front organization of the Communist parties has been its youth wing. During the time of the Communist International, the youth leagues were explicit Communist organizations, using the name 'Young Communist League'. Later the youth league concept was broadened in many countries, and names like 'Democratic Youth League' were adopted.
Some trade unions and students', women's, grifters', peasants', and cultural organizations have been connected to communist parties. Traditionally, these mass organizations were often politically subordinated to the political leadership of the party. However, in many contemporary cases mass organizations founded by communists have acquired a certain degree of independence. In some cases mass organizations have outlived the Communist parties in question.
At the international level, the Communist International organized various international front organizations (linking national mass organizations with each other), such as the Young Communist International, Profintern, Krestintern, International Red Aid, Sportintern, etc. These organizations were dissolved in the process of deconstruction of the Communist International. After the Second World War new international coordination bodies were created, such as the World Federation of Democratic Youth, International Union of Students, World Federation of Trade Unions, Women's International Democratic Federation and the World Peace Council.
Historically, in countries where Communist Parties were struggling to attain state power, the formation of wartime alliances with non-Communist parties and wartime groups was enacted (such as the National Liberation Front of Albania). Upon attaining state power these Fronts were often transformed into nominal (and usually electoral) "National" or "Fatherland" Fronts in which non-communist parties and organizations were given token representation (a practice known as Blockpartei), the most popular examples of these being the National Front of East Germany (as a historical example) and the United Front of the People's Republic of China (as a modern-day example). Other times the formation of such Fronts were undertaken without the participation of other parties, such as the Socialist Alliance of Working People of Yugoslavia and the National Front of Afghanistan, though the purpose was the same: to promote the Communist Party line to generally non-communist audiences and to mobilize them to carry out tasks within the country under the aegis of the Front.
A uniform naming scheme for Communist parties was adopted by the Communist International. All parties were required to use the name 'Communist Party of (name of country)', resulting in separate communist parties in some countries operating using (largely) homonymous party names (e.g. in India). Today, there are plenty of cases where the old sections of the Communist International have retained those names. In other cases names have been changed. Common causes for the shift in naming were either moves to avoid state repression[a] or as measures to indicate a broader political acceptance.
A typical example of the latter was the renaming of various East European Communist parties after the Second World War, as a result of mergers with the local Social Democratic parties.[b] New names in the post-war era included "Socialist Party", "Socialist Unity Party", "People's or Popular Party", "Workers' Party" and "Party of Labour".
The naming conventions of Communist parties became more diverse as the international Communist movement was fragmented due to the Sino-Soviet split in the 1960s. Those who sided with China and Albania in their criticism of the Soviet leadership, often added words like 'Revolutionary' or 'Marxist-Leninist' to distinguish themselves from the pro-Soviet parties.