FACTBOX: Delegates add up in presidential race

(Reuters) - Delegates, not voters, will determine each party's nominee in the November 2008 presidential election.

Here are some facts about how delegates are selected in each party:

DEMOCRATS

* Democrats divide their 4,049 delegates based on the number of voters in each state and how reliably those voters support Democrats. Democratic-dominated Massachusetts gets 121 delegates while reliably Republican Indiana gets 79, though both states have roughly the same population.

* Primary or caucus results determine four-fifths of the convention delegates. A majority of 2,025 Democratic delegates are needed to secure the nomination. Delegates are awarded on a proportional basis -- a candidate who loses the statewide vote can still win delegates.

* The remaining 796 "superdelegates," party insiders and elected officials, can support whomever they want.

* As of January 30, Clinton led with 232 delegates, followed by Obama with 158, CNN estimated. Former North Carolina Sen. John Edwards has dropped out of the race, but his 62 delegates could determine the winner in the unlikely event a clear leader has not emerged by the party's August convention.

REPUBLICANS

* Republicans allocate their 2,380 delegates to each state and territory based roughly on population, with reliably Republican states awarded bonus delegates. A majority of 1,191 delegates is needed to win the nomination.