Supermajority

A supermajority or supra-majority or a qualified majority, is a requirement for a proposal to gain a specified level of support which is greater than the threshold of one-half used for majority.

Related concepts regarding alternatives to the majority vote requirement include a majority of the entire membership and a majority of the fixed membership.

A supermajority can also be specified based on the entire membership or fixed membership rather than on those present and voting.

Parliamentary procedure requires that any action of a deliberative assembly that may alter the rights of a minority has a supermajority requirement, such as a two-thirds vote.

Changes to constitutions, especially those with entrenched clauses, commonly require supermajority support in a legislature.

History

The first known use of a supermajority rule was in the 100s BCE in ancient Rome.[1]

Pope Alexander III introduced the use of supermajority rule for papal elections at the Third Lateran Council in 1179.[2]

In the Democratic Party of the United States, the determination of a presidential nominee once required the votes of two-thirds of delegates to the Democratic National Convention. This rule was adopted in the party's first presidential nominating convention—the 1832 Democratic National Convention.[3] The two-thirds rule gave southern Democrats an effective veto over any presidential nominee for many years, until the rule's abolition at the 1936 Democratic National Convention.[4]