of the day. Congress is constantly changing and is constantly in flux. [ 9 ] In recent times, the American south and west have gained House seats according to demographic changes recorded by the census and includes more minorities and women although both groups are still underrepresented, according to one view. [ 9 ] While power balances among the different parts of government continue to change, the internal structure of Congress is important to understand along with its interactions with so-called intermediary institutions such as political parties, civic associations, interest groups, and the mass media. [ 8 ] The Congress of the United States serves two distinct purposes that overlap: local representation to the federal government of a congressional district by representatives and a state's at-large representation to the federal government by senators. Government powerlessness led to the Convention of 1787 which proposed a revised constitution with a two–chamber or bicameral congress. [ 16 ] Smaller states argued for equal representation for each state. [ 17 ] The two-chamber structure had functioned well in state governments. [ 9 ] A compromise plan was adopted with representatives chosen by population (benefitting larger states) and exactly two senators chosen by state governments (benefitting smaller states). [ 9 ] [ 18 ] The ratified constitution created a federal structure with two overlapping power centers so that each citizen as an individual was subjected to both the power of state government and the national government. [ 19 ] [ 20 ] [ 21 ]