With Mississippi primary votes now tallied, the delegate count for Senator Barack Obama totals 1,598. Senator Hillary Rodham Clinton has 1,487, according to the AP count.
It takes 2,025 delegates to win the Democratic presidential nomination. The convention is set for this summer.
The Associated Press tracks delegates by a set formula. It calculates the number of national convention delegates won by candidates in each presidential primary or caucus, based on state and national party rules, and by interviewing unpledged delegates to obtain their preferences.