One noteworthy item that has been under the radar is the slow but steady movement of the superdelegates towards Obama. The table below shows the estimates of various news sources of Barack Obama's lead over Hillary Clinton on March 6 (thus after the Texas and Ohio elections) and today. Two things stand out. First, the spread is much less. The various sources are beginning to converge on the same numbers as more and more superdelegates announce their positions. Second, Obama's lead is slowly but inexorably growing. His lead has grown by 30 in the past month. After Pennsylvania and North Carolina vote, it will probably still be something around 120-130 because Clinton's expected win in Pennsylvania is likely to be cancelled by Obama's expected win in North Carolina. CQPolitics has a story on the math. Bottom line: Obama has the holy trinity on his side: most delegates, most states, and most popular votes. To convince the remaining superdelegates to go for her, she has to take the lead in at least one of the categories by doing very well in the remaining primaries and caucuses.
http://www.electoral-vote.com/evp2008/Pres/Maps/Apr03.html#news