The number of delegates they have earned so far is less important now, because neither of them can get the minimum for nomination now (as in the McCain case). Superdelegates will have to decide who is the one. 

Besides, a lot of states voted before the NAFTA scandal. Some people may have changed their mind for obama now, which would influence their votes in the general election.  Superdelegates need to keep that in mind.

Both of Obama and Clinton have connections in D.C. What's the big deal?