With a total of 4,049 delegate votes to be cast at the convention, a candidate must win a majority (2,025) of the votes to win the nomination.

The system is, however, more complicated than merely winning half the country. The delegate votes are broken down into two groups:

1. state allocated delegates whose vote at the convention is tied or pledged to the results of the state primary or caucus (3,253 delegate votes) awarded to candidates through a proportional representation system and

2. a group of superdelegates. (796 delegate votes) that are not pledged to any candidate.

State Allocated Delegates

For each state, the state allocated delegates further divided. There are:

*District Delegates

*At-Large Delegates, and

*Pledged Party & Elected Official Delegates.

District Delegates District delegates represent specific congressional districts within the state. Because the Democratic Party mainly awards candidates delegate votes through a proportional representation system, a candidate will receive the number of delegate votes equivalent to the proportion of the votes he receives within that district, provided he or she receives more than 15% of the vote there.

At-Large Delegates & Pledged Party & Elected Official Delegates At-large delegates and pledged party and elected official delegates represent the state as a whole. They are also awarded to candidates on a proportional representation system, rewarding delegate votes to a candidate based, however, on the proportion of the vote the candidate receives in the state as a whole, as long as he or she receives more than 15% of the vote in the state.

This system of awarding candidates state delegate votes based on a proportional system that captures voters' wishes at both a local and state level can mean, though, that a candidate can win the state in terms of the number of votes he or she receives, but actually win less delegates. In 2008, this has happened in both Iowa and Nevada. In Iowa, Hillary Clinton placed third to Barack Obama and John Edwards in the polling based on the number of votes she received (Obama 38%, Edwards 30%, Clinton 29%), but actually won more delegates than second place winner, John Edwards (Obama received 16 delegates, Clinton 15, and Edwards 14). In Nevada, Obama won 6% less of the statewide vote than Clinton, but received 1 more delegate than she did.

Superdelegates

In addition to the state allocated delegate votes, there are 796 delegate votes left uncommitted and at the discretion of the delegate casting the vote. These delegates are known as Superdelegates. Superdelegates are the unpledged state party leaders and elected officials and other add-on delegates. They include members of the DNC, members of Congress that are not pledged state delegate votes, Democratic governors (except those that are members of the DNC), and distinguished party leaders (typically current and former presidents, vice presidents, leaders of the House and Senate, and former DNC chairmen). While this group tends to vote for the frontrunner, they are courted by candidates for endorsements and a pledged delegate vote at the convention.

If, after the primary and caucus season, no candidate has won a majority of delegates candidates a presidential nominee will be selected through a brokered convention that requires deal-making at the convention. In this situation, superdelegates may play a larger role in the nomination than normally occurs when a frontrunner emerges from the primaries.