A government in which the ideas of a single leader or small group dominate is known as?

The term that describes a government where the ideas of a single leader or a small group dominate is "totalitarian." In a totalitarian system, the state seeks to control nearly every aspect of public and private life. This is characterized by the concentration of power in a single authority or a small elite, often accompanied by the suppression of dissent and civil liberties.

Totalitarian regimes often utilize propaganda, surveillance, and state control of the media to maintain their grip on power and manipulate the thoughts and behaviors of the populace. The leaders or group in a totalitarian government typically enforce strict obedience and have little tolerance for opposition, which contrasts sharply with democratic systems where power is distributed among many and decisions are made through collective voting processes.

The other terms, while related to governance, do not fit this specific description. Democracy emphasizes participation and representation, anarchy implies the absence of government, and monarchy refers to rule by a king or queen, which may or may not be totalitarian depending on how power is exercised.