Sista debatten inför dramatisk supertisdag

Supertisdagen (engelska: Super Tuesday) är en tisdag i februari eller mars under de år då det hålls presidentval i USA, under vilken en stor del av USA:s delstater håller primärval eller nomineringsval för att ta fram den demokratiska och den republikanska kandidaten till presidentposten. Den är en viktig dag i amerikanska primärvalskampanjer då det är den dagen då flest delstater håller primärval. Att vinna stort på supertisdagen ger ofta en presidentkandidat en tillräcklig knuff för att gå segrande ur hela primärvalsprocessen. Exakt vilka delstater som har primärval på supertisdagen och hur många som har det varierar från gång till gång. Demokraternas primärval är alltid proportionella, det vill säga kandidaten tilldelas delegater beroende på hur stor andel av rösterna han eller hon får. Republikanerna däremot har majoritetsval i flera av de folkrikaste delstaterna, vilket innebär att vinnaren får alla delegater. Begreppet supertisdag slog igenom 1988 då demokraterna i flera delstater i Södern bestämde sig för att hålla sina primärval samtidigt, den 8 mars. På så sätt hoppades de få större inflytande och få fram en mer konservativ presidentkandidat. Planen misslyckades dock. Delstaterna splittrades mellan Al Gore, Jesse Jackson och Michael Dukakis och den liberale Dukakis blev till slut demokraternas presidentkandidat. Supertisdagar har sedan hållits 10 mars 1992, 12 mars 1996, 7 mars 2000, 2 mars 2004, 5 februari 2008 och 6 mars 2012.

The series of presidential primary elections and caucuses held in each U.S. state and territory is part of the nominating process of United States presidential elections. This process was never included in the United States Constitution; it was created over time by the political parties. Some states only hold primary elections, some only hold caucuses, and others use a combination of both. These primaries and caucuses are staggered generally between January and June before the general election in November. The primary elections are run by state and local governments, while caucuses are private events that are directly run by the political parties themselves. A state's primary election or caucus is usually an indirect election: instead of voters directly selecting a particular person running for President, they determine how many delegates each party's national convention will receive from their respective state. These delegates then in turn select their party's presidential nominee. Each party determines how many delegates are allocated to each state. Along with those delegates chosen during the primaries and caucuses, state delegations to both the Democratic and Republican conventions also include "unpledged" delegates, usually current and former elected officeholders and party leaders, who can vote for whomever they want. This system of presidential primaries and caucuses is somewhat controversial because of its staggered nature. The major advantage is that candidates can concentrate their resources in each area of the country one at a time instead of campaigning in every state simultaneously. However, the overall results may not be representative of the U.S. electorate as a whole: voters in Iowa, New Hampshire and other small states which traditionally hold their primaries and caucuses first usually have a major impact on the races, while voters in California and other large states which traditionally hold their primaries last in June generally end up having no say because the races are usually over by then. As a result, more states vie for earlier primaries to claim a greater influence in the process.