When the United States fought its war for independence from Great Britain, the various colonies sent delegates to an assembly known to history as the Continental Congress. This loose organization was formalized by the adoption of the Articles of Confederation, which called its legislative body the “United States in Congress Assembled.”
Regardless of the name by which this congress was known or its exact power or structure, each of the colonies/states had one vote (regardless of the number of delegates it sent). When the government under the Articles of Confederation proved ineffective and the Constitutional Convention was debating the composition of the legislature to be proposed, larger states urged that voting power be proportional to population (the Virginia Plan), while smaller states sought to retain equal voting power (the New Jersey Plan). Ultimately the convention agreed to the Connecticut Compromise, which provided for two houses in the new Congress: the House of Representatives (states represented in proportion to population) and the Senate (each state choosing two senators).
This two-house structure for a legislature is called bicameralism, from the Latin word camera, meaning “chamber” or “room.” (In this context the words “house” and “chamber” are synonymous.) The Congress under the Constitution was of course not the first bicameral legislative body. Not only did the British Parliament (whose authority over America was denied by the Declaration of Independence) have two chambers, the House of Lords and the House of Commons, but two houses were the usual, if not the sole, manner of organization of colonial, and later state, legislatures.
As the Connecticut Compromise shows, bicameralism allows for different methods of selection or representation. (Until the Seventeenth Amendment, senators were chosen by state legislatures rather than popular vote.) Until the reapportionment cases of the 1960s, some states used factors other than population equality to apportion seats on one house of their state legislature. In New Jersey,for example, each county was formerly represented by one senator, until the rejection of the so-called “federal analogy” by Reynolds v. Sims, 377 U.S. 533, 84 S. Ct. 1362, 12 L. Ed. 2d 506 (1964), eventually resulted in the current structure, in place since the 1973 election: 40 legislative districts, with substantially equal population, each electing one senator and two members of the general assembly.
It is this method that is described by the title of this post. Each district is represented by legislators elected by the same voters (and, in three out of five elections, at the same time). The result (encouraged by the gerrymandering used after each census to create the districts) is that almost every (if not every) district is represented by three people from the same party. What, then, is the point of having two houses? In a future post I will suggest an alternate method of selecting senators that might answer this question.