The Democratic party decided Saturday to count Michigan and Florida delegates at a half-vote value each.
The decision, which comes after months of debate, means neither Sen. Hillary Clinton (D-NY) nor Sen. Barack Obama (D-Ill.) will have enough votes to officially clinch the presidential nomination unless one of them drops out before the August convention.
The motion passed on a 19-8 margin, with no abstentions. The votes had initially been stripped as a result of the states moving their primary dates up against party wishes.
The ruling increases the number of delegates needed to win to 2,118. Obama is 66 delegates short, but maintains a lead over Clinton.
Clinton's chief delegate counter says he has been instructed to reserve her right to appeal the decision. An appeal could drag the matter out until the August convention.
Clinton wins WV primary, Obama still nomination leader