Concurrent majority is a constitutional method of enabling minorities to block the actions of majorities by allowing minority groups veto power over laws. In the United States, the most vocal proponents of the theory have tended to be minority groups, such as farmers in an industrial society or slave-owning Southerners protesting national policies that encroached on their hereditary privileges and business interests. The concurrent majority is intended to prevent the tyranny of the majority that can otherwise occur in an unlimited democracy.
Prior to the American Revolution, most governments were controlled by small minorities of ruling elites. In these governments, most of the population was completely disfranchised, even in countries like Switzerland whose governments (local, regional, and federal) were constitutionally democratic by modern standards. The conception of government that materialized during the separation of the United States from the United Kingdom marked movement away from such control towards wider enfranchisement. The problem of tyranny then became a problem of limiting the power of a majority.
Even so, the widening of the franchise caused concern. The framers of the United States Constitution, even while reiterating that the people held national sovereignty, worked to ensure that a simple majority of voters could not infringe upon the liberty of the rest of the people. One protection from this was separation of powers, such as bicameralism in the Congress and the three branches of the national government: legislative, executive, and judicial.
Having two houses was intended to serve as a brake on popular movements that might threaten particular groups, with the House representing the common people and the Senate defending the interests of the state governments. The House was to be elected by popular vote, while the Senate were appointed by state legislators. Executive veto and the implied power of judicial review by the Supreme Court created further obstacles to absolute majority rule.