Term limit

A term limit is a law that limits the number of terms an officeholder may serve in a particular elected office. When term limits are found in presidential systems, they act as a method to reduce the potential for monopoly. This is when a leader effectively becomes a "president for life". Term limits are intended to protect a democracy from becoming a de facto dictatorship. Sometimes, there is an absolute limit on the number of terms an officeholder can serve. In other cases, the restrictions are merely on the number of consecutive (one directly following the other) terms.
History.
Ancient Greece and Ancient Rome, two early civilizations which had elected offices, both imposed limits on some positions. In the ancient Athenian democracy, only offices selected by sortition were subject to terms limits. They included one term of one year for each office, except members of the Council of Five Hundred, where the council was changed every year.
In the Roman Republic, a law was passed imposing a limit of a single term on the office of censor. The annual magistrates - tribune of the plebs, aedile, quaestor, praetor, and consul—were forbidden reelection until a number of years had passed. Also there was a term limit of 6 months for a dictator.
In the United States.
The United States Constitution and many state constitutions have term limits for certain offices. The Twenty-second Amendment to the United States Constitution sets a term limit for the office of President of the United States. It states that "no person may be elected more than twice". It adds, "no person who has held the office of President, or acted as President, for more than two years of a term to which some other person was elected President shall be elected to the office of the President more than once." In addition, 23 states passed laws on term limits for their representatives in Congress. These laws are no longer enforceable, however. In 1995, the Supreme Court of the United States overturned congressional term limits in "U.S. Term Limits, Inc. v. Thornton". They ruled that state governments cannot limit the terms of members of the national government.