Although Maine technically sent 24 pledged delegates to the Democratic National Convention, John Knutson, the superdelegate Chairman of the Maine Democratic Party, had pledged to support whoever won the majority of the vote, making the total number of pledged delegates effectively 25.
The Maine Democratic Caucus was a closed caucus open to all Democratic voters. New voters and nonpartisan voters could register as Democrats at the door, while members of other parties must have changed their party registration by January 26, 2008. In addition, absentee ballots were permitted for the disabled and those in the military who could not personally attend.
At the caucus, participants gathered in groups among presidential preference. Unlike most other caucuses, there was no 15-percent minimum threshold, as long as a candidate had enough votes to elect a whole delegate after rounding. Re-caucusing after the first preference groups was divided was permitted among all participants. After dividing presidential delegates, voters were elected to be delegates to the Maine Democratic Party State Convention on May 31, 2008, pledged but not bound to their candidate. Only state delegates are reported by the party. At the state level, delegates were selected for the Democratic National Convention; these delegates were bound.