Clinton has strong support from many of the "superdelegates".
Per CNN: "Superdelegates in the Democratic Party are typically members of the Democratic National Committee, elected officials like senators or governors, or party leaders. They do not have to indicate a candidate preference and do not have to compete for their position. If a superdelegate dies or is unable to participate at the convention, alternates do not replace that delegate, which would reduce the total delegates number and the "magic number" needed to clinch the nomination."
So while Obama has a slight edge in elected delegates, Clinton still has a sizable margin in overall delegates.