In the ongoing US presidential nomination race, victory is not defined by how many states a candidate wins, but how many delegates he or she can grab.
Why delegates matter so much?
It is simple because finally, it is up to the delegates who go to the Democratic and Republican national conventions to officially choose the nominees for the presidency.
So anyone who wants to run for the US presidency representing either party has to try to win the support of as many delegates as possible in the state primaries and caucuses between January and June.
"It's all about the delegates," as Barack Obama, the leading Democratic candidate once said.
This year, the Democratic convention in August will have 4,049 delegates in total and the Republican convention in September will have 2,380.
To win the party nomination, a candidate needs a simple majority (50 percent of the votes plus one vote) among all of the delegates at the conventions. So the winning number of votes for a Democratic candidate is 2,025, and 1,191 for Republican.
However, not all of the delegates are won in the January-June primary elections. For both parties, there are two types of delegates, pledged and unpledged.
Pledged delegates, which account for 80 percent of the total delegates for both parties, are determined by the result of the primary or caucus in their state.
Unpledged delegates are appointed not elected, and they are free to choose which candidate to support. They are called "super-delegates" by the Democratic party.
In both parties, unpledged delegates account for 20 percent of the total, and are mostly high-ranking party officials, members of Congress and state governors.
In a close race like the current Democratic contest, candidates have to make a big effort to woo the unpledged delegates.
The number of delegates allocated to a state or a territory is based on its size, population and voting records. The most populous states -- California, Texas and New York -- have many times more delegates than the smallest states.
For Democrats, the number of pledged delegates a candidate wins in a primary or caucus is always proportionate to the number of votes he or she receives. But any candidate must win at least 15 percent of the votes to get the proportionate delegates.
For Republicans, some states operate a winner-takes-all system, where the candidate who wins the most support state-wide gets all the delegates. In others, the winner-takes-all principle operates at the level of congressional districts: the candidate who does best in a district wins all the delegates available in that district.
The Republicans also use a proportional system in some states.
If no candidate accumulates a winning number of delegates before the convention, the rivals may have to negotiate.
(Xinhua News Agency February 13, 2008)