The AP tracks the delegate races by projecting the number of pledged 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. In some states, like Iowa and Nevada, local precinct caucuses are the first stage in the allocation process. The AP uses preferences expressed in those caucuses to project the number of national convention delegates each candidate will have when they are chosen at county, congressional district or state conventions. Unpledged Democratic delegates, known as "super delegates," are not bound by the results of the primary or caucus and can vote for any candidate they choose at the party's national convention, Aug. 25-28 in Denver. The elected officials, Democratic National Committee members and party leaders who are "super delegates" can change their presidential preferences at any time, and the AP changes delegate numbers accordingly when they do. Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more