Some perspective on the primaries
Concerning Tuesday specifically, take a look at this post. Hillary's lead over Bernie both in the popular vote and in pledged delegates (that is, excluding the unelected "superdelegates") actually increased on Tuesday, reflecting the fact that her much-discussed loss in Michigan was extremely close while her Mississippi win was a blowout, 83%-to-17%. The concern expressed by some bloggers that the superdelegates are an un-democratic distortion of the nominating process shouldn't obscure the fact that, even without them, Hillary is ahead by a sizable margin.
If the Michigan result (and the inaccuracy of the polls there) is replicated in other somewhat-similar states such as Ohio and Illinois, Hillary may have a problem, but that's speculation at this point. Right now, even taking Michigan into account, she's still unequivocally winning.