专政 (zhuānzhèng) is not just a translation of “dictatorship”; it's a foundational concept in the political theory of the People's Republic of China, rooted in Marxism-Leninism.
The key phrase to understand is 人民民主专政 (rénmín mínzhǔ zhuānzhèng), the “People's Democratic Dictatorship.”
Comparison with Western “Dictatorship”: In the West, “democracy” and “dictatorship” are seen as mutually exclusive opposites. If a system is a dictatorship, it cannot be democratic, and vice-versa. The term “dictatorship” carries an overwhelmingly negative connotation of oppression and tyranny.
The Chinese Political Interpretation: In PRC political theory, these two concepts are presented as two sides of the same coin. The system is a democracy for the vast majority of “the people” (人民) but a dictatorship for the enemies of the people and the state (e.g., counter-revolutionaries, foreign agents). In this view, the `专政` function is a necessary tool to protect the people's democracy from being subverted. Therefore, within this official framework, `专政` is not inherently negative; it's a necessary function of the state.
Understanding this dualistic interpretation is crucial to reading Chinese government documents and understanding the state's official self-perception.