Formally in force but often ignored in practice, the Constitution of 1853 created a checks-and-balances system of executive, legislative, and judicial branches resembling that of the United States. The bicameral Congreso Nacional (National Congress—the legislative branch) consists of a 257-member Cámara de Diputados (Chamber of Deputies) and a 72-member Senado (Senate), whose members represent 23 provinces and the Ciudad Autónoma de Buenos Aires (Autonomous City of Buenos Aires). The Cámara is subject to redistricting following each decennial census.

In reality, however, the president wields great discretionary powers, often governs by decree, and frequently intervenes in provincial affairs. A 1994 constitutional amendment reduced the executive’s term from six years to four, but also allowed him or her to run for immediate reelection to a second term. The same amendment abolished a provision that required the president to be Roman Catholic.

Argentina’s constitution is federal; each province and the city of Buenos Aires has its own autonomous government. Its federalism is one-sided, though, as the central government funds provincial governments through revenue-sharing; in practice, this is a burden, as fiscally irresponsible provinces can blame revenue shortages on Buenos Aires. La Rioja, for instance, collects only 10 percent of its budget in local tax revenue.

In addition to the city of Buenos Aires and 23 provinces, Argentina claims the Islas del Atlántico Sur (including the British-ruled Falkland/Malvinas Islands and South Georgia) and Antártida Argentina (a wedge of Antarctica below 60° south latitude between 25° and 74° west longitude). While Argentina is persistent and vocal in its claims to the Falklands and South Georgia, it acknowledges that Antarctic claims are on hold by international treaty.