A rubber stamp, as a political metaphor, refers to a person or institution with considerable de jure power but little de facto power; one that rarely disagrees with more powerful organs.
The term itself likely stems from the commonplace practice of subordinate employees or officials being deputized and given the authority to sign the name of their superior or employer. In situations where this superior official's signature may frequently be required for routine paperwork, a literal rubber stamp is used, with a likeness of their hand-written signature. In essence, the term is meant to convey an endorsement without careful thought or personal investment in the outcome, especially since it is usually expected as the stamper's duty to do so. In the situation where a dictator's legislature is a "rubber stamp", the orders they are meant to endorse are formalities they are expected to legitimize, and are usually done to create the superficial appearance of legislative and dictatorial harmony rather than because they have actual power. Historian Edward S. Ellis called this type of parliament a "toy parliament", in reference to Ottoman Sultan Abdul Hamid II's Turkish parliament, created in 1876 with the sole purpose of appeasing European powers.
Conversely, in a constitutional monarchy, the monarch is typically a "rubber stamp" to an elected parliament, even if he or she legally possesses considerable reserve powers and/or disagrees with the parliament's decisions.
Famous quotes containing the words rubber and/or stamp:
“First, are you our sort of a person?
Do you wear
A glass eye, false teeth or a crutch,
A brace or a hook,
Rubber breasts or a rubber crotch,
Stitches to show something’s missing?”
—Sylvia Plath (1932–1963)
“If we can’t stamp out literature in the country, we can at least stop its being brought in from outside.”
—Evelyn Waugh (1903–1966)