Superdelegates are elected officials and party leaders who are free to side with any presidential candidate they choose, right up until the nominee is officially picked at next summer's convention in Denver. But Florida and Michigan, at least at the moment, don't have any because both states decided to hold primaries in January, in violation of DNC rules.
Superdelegates tend to reflect the sentiments of the party's establishment, so it's little surprise that Clinton suffers the most from that decision – a CBS News estimate shows that the number of superdelegates backing the New York senator has dropped from 184 in a November survey to 171 now.
Clinton bore the brunt of the decision, but others were hit, too. Barack Obama lost 4 superdelegates to fall to 67. John Edwards and Dennis Kucinich lost 1 superdelegate each.
The actual impact of this move on the race for the Democratic nomination is likely to be small. Superdelegates are quick to rally around a party's front-runner, basing their decisions on the results of the upcoming primaries and caucuses. And the eventual nominee is likely to persuade the DNC that Florida's and Michigan's delegates get seated at the convention, anyway. But in the unlikely event of a brokered convention, these relatively minor changes could end up playing a role.