The United States is a country in the Western Hemisphere. It consists of forty-eight contiguous states on the North American continent; Alaska, an enormous peninsula which forms the northwestern most part of North America, and Hawaii, an archipelago in the Pacific Ocean. It also holds several United States territories in the Pacific and Caribbean. The term "United States",... when used in the geographical sense, means the continental United States, Alaska, Hawaii, Puerto Rico, Guam, and the Virgin Islands of the United States.[1] The country shares land borders with Canada and Mexico and water borders with Russia, the United Kingdom, and The Bahamas. Politics of the United States takes place in the framework of a presidential, federal republic where the President of the United States (the head of state and head of government), United States Congress, and judiciary share federal powers, and the federal government shares sovereignty with the state governments. Federal and state elections generally take place within the lines of a two-party system, although this is not enshrined in law. The executive branch is headed by the President and is independent of the legislature. Legislative power is vested in the two chambers of Congress, the Senate and the House of Representatives. Judicial power is exercised by the judicial branch (or judiciary), composed of the Supreme Court and lower federal courts. The judiciary's function is to interpret the United States Constitution as well as federal laws and regulations. This includes resolving disputes between the executive and legislative branches. The federal government of the United States was established by the Constitution. American politics has been dominated by two parties, the Democratic Party and the Republican Party, since the American Civil War, although other parties have also existed. Major differences between the political system of the United States and that of most other developed democracies are the power of the Senate as the upper house of the legislature, the wide scope of power of the Supreme Court, the separation of powers between the legislature and the executive government, and the dominance of the two main parties – the United States being one of the world's developed democracies in which third parties have the least political influence. Political ideologies in the United States vary considerably. Persons in the U.S. generally classify themselves either as adhering to American liberalism, American conservatism or as moderates. American liberalism aims at the preservation and extension of human, social and civil rights as well as the government guaranteed provision of positive rights. It combines social progressivism and to some extent, ordoliberalism and is highly similar to European social liberalism of parties like the British Liberal Democrats, Dutch Democrats 66 and Belgian Flemish Liberals and Democrats. American conservatism commonly refers to a combination of economic liberalism and social conservatism and to an extent, libertarianism. It aims at protecting traditional values (especially on social issues) while promoting the concept of small government. The ideological position a person or party takes may be described in terms of social and economic policy. The ideological positions a person assumes on social and economic policy issues may differ in their position on the political spectrum. Milton Friedman, for example, was left-of-center on social issues but right-of-center on fiscal matters. [1] Several ideological demographics may be identified in addition to or as subgroups of liberals and conservatives with nearly every possible ideology being found in the general population. The U.S. has a de facto two-party system. The Democratic Party generally represents liberal ideals, while the Republican Party commonly represents conservative ideals. Smaller parties such as the Libertarian Party and the Greens play a minor role in American politics and are not deemed able to capture the presidency.[2] The size of ideological groups varies slightly depending on the poll. According to a 2007 poll, 35% of Americans identified as moderate, 36% as "conservative" and 25% as "liberal."[3] In a 2005 study, the Pew Research Center identified nine typological groups. Three groups were identified as part of each, "the left," "the middle," and "the right." In this categorization system, "the right" roughly represents the Republican base, those on the "the left" the Democratic base and those in "the middle" independents. Within the left are the largely secular and anti-war "Liberals", the socially conservative but economically left"Conservative Democrats", and the economically "Disadvantaged Democrats" who favor an extended welfare state. In "the middle" are the optimistic and upwardly mobile "Upbeats", the discouraged and
mistrusting "Disaffecteds," and the disenfranchised "Bystanders." The right compromises the highly pro-business "Enterprisers," the highly religious "Social Conservatives" (also known as the Christian right), and the "Pro-Government Conservatives" who are largely conservative on social issues but support government intervention to better their economic disposition.[4] The economy of the United States is the largest national economy in the world.[11] Its gross domestic product (GDP) was estimated as $14.3 trillion in 2008.[12] The U.S. economy maintains a high level of output per person (GDP per capita, $46,800 in 2008, ranked at around number ten in the world). The U.S. economy has maintained a stable overall GDP growth rate, a low unemployment rate, and high levels of research and capital investment funded by both national and, because of decreasing saving rates, increasingly by foreign investors. In 2008, seventy-two percent of the economic activity in the U.S. came from consumers.[13] Major economic concerns in the U.S. include external debt, entitlement liabilities for retiring baby boomers who have already begun withdrawing from their Social Security accounts, corporate debt, mortgage debt, a low savings rate, falling house prices, and a large current account deficit. As of September 2008, the gross U.S. external debt was over $13.6 trillion,[14] the most external debt of any country in the world.[15] The 2008 estimate of the United States public debt was 73% of GDP.[16] As of June 2009, the total U.S. federal debt was approximately $11.4 trillion,[7] about $37,348 per capita.