Superdelegates are Democratic governors, members of Congress and party officials.
Winning the majority of the pledged delegates means that although there are three contests left, Obama is already the choice of the majority of Democrats in the country.
Combined with the number of superdelegates, Obama now has 1,932total delegates, compared to Clinton's 1,753.
A candidate needs 2,026 delegates to win the Democratic nomination.
As Obama bags more superdelegates each day and can still win dozens of pledged delegates in the three remaining primaries, he will likely be able to reach the magic number of 2,026 on June 3, the last day of the Democratic primaries.
Within reach
It is still premature for Obama to declare himself the Democratic nominee at this point, but he is approaching that goal by nearly every measure.
He has won 32 of the past 53 Democratic primaries and caucuses, versus Clinton's 21.
He has won more popular votes, as the votes in Michigan and Florida are not counted in punishment for the two states' violation of Democratic Party election rules.
Meanwhile, Obama continues to pull in the backing of superdelegates, which is necessary to formally put him ahead in the Democratic contest.