conventions held by each political party. This process was never included in the Constitution, and thus evolved over time by the political parties to clear the field of candidates. The primary elections are run by state and local governments, while the caucuses are organized directly by the political parties. Some states hold only primary elections, some hold only caucuses, and others use a combination of both. These primaries and caucuses are staggered generally between January and June before the federal election, with Iowa and New Hampshire traditionally holding the first presidential state caucus and primary, respectively. Like the general election, presidential caucuses or primaries are indirect elections. The major political parties officially vote for their presidential candidate at their respective nominating conventions, usually all held in the summer before the federal election. Depending on each state's law and state's political party rules, when voters cast ballots for a candidate in a presidential caucus or primary, they may be voting to award delegates "bound" to vote for a candidate at the presidential nominating conventions, or they may simply be expressing an opinion that the state party is not bound to follow in selecting delegates to their respective national convention. Unlike the general election, voters in the U.S. territories can also elect delegates to the national conventions. Furthermore, each political party can determine how many delegates to allocate to each state and territory. In 2012 for example, the Democratic and Republican party conventions each used two different formulas to allocate delegates. The Democrats-based theirs on two main factors: the proportion of votes each state gave to the Democratic candidate in the previous three presidential elections, and the number of electoral votes each state had in the Electoral College. In contrast, the Republicans assigned to each state 10 delegates, plus three delegates per congressional district. Both parties then gave a fixed number of delegates to each territory, and finally bonus delegates to states and territories that passed certain criteria. Along with delegates chosen during primaries and caucuses, state and U.S. territory delegations to both the Democratic and Republican party conventions also include "unpledged" delegates who have a vote. For Republicans, they consist of the three top party officials from each state and territory. Democrats have a more expansive group of unpledged delegates called "superdelegates", who are party leaders and elected officials. Each party's presidential candidate also chooses a vice presidential nominee to run