Before American voters take to the polls on November 6, they will first narrow the field of candidates in a series of primaries, caucuses, and elections held in each of the 50 states.

Primary
A primary election is an election organized by the main political parties of each state and is intended to select the candidate that the state’s delegates will choose at the party’s national convention. Generally, primary elections are closed, meaning that only registered members of that party may vote in the primary. Some states allow independents to cast a vote in their primaries.

Caucus
A caucus is a meeting of party members in which they decide which candidate to support. Unlike a primary, which is done by secret ballot, in a caucus undecided party members can be persuaded or encouraged by other party members to support a specific candidate. Caucuses allow for more discussion and debate within the party until, at the end of the meeting, organizers count the number of votes for each candidate and determine their number of delegates.

By tradition, Iowa holds the first caucus and New Hampshire holds the first primary. Although not always the case, the outcome of these two early contests can often determine the outcome of the party’s nomination, as winners in Iowa and New Hampshire can continue to gain momentum among voters and donors, while a poor showing in the early contests can cause a candidate to drop out of the race. This perceived prominence of early primaries and caucuses has encouraged states to try to “front load” the primary calendar and schedule their primaries early in the year, contradicting the parties’ intention that the primary system will “vet” candidates and not simply favor the most well-known or well-funded candidate.

The party’s candidate is officially nominated at the party convention in the summer before the general election, and the states’ delegates typically follow the outcome of the primary election or caucus when casting their votes for the nomination.

In 2012, only the Republican Party will have primaries and caucuses, followed by its convention in August in Tampa Bay, Florida. The Democratic Party’s candidate is incumbent Barack Obama, who will formally accept the nomination at the convention in Charlotte, North Carolina, in September.

Selected upcoming primaries and caucuses:

January 3, 2012
Iowa (caucus)

January 10, 2012
New Hampshire (primary)

January 21, 2012
South Carolina (primary)

January 31, 2012
Florida (primary)

February 4, 2012
Nevada (caucus)

March 6, 2012 / Super Tuesday
Alaska (caucus)
Georgia (primary)
Idaho (caucus)
Massachusetts (primary)
North Dakota (caucus)
Ohio (primary)
Oklahoma (primary)
Tennessee (primary)
Vermont (primary)
Virginia (primary)

April 3, 2012
District of Columbia (primary)
Maryland (primary)
Wisconsin (primary)
Texas (primary)

April 24, 2012
Connecticut (primary)
Delaware (primary)
New York (primary)
Pennsylvania (primary)
Rhode Island (primary)

June 5, 2012
California (primary)
Montana (primary)
New Jersey (primary)
New Mexico (primary)
South Dakota (primary)