HRC has been allowed to declare several states "Must Win", Barack Obama should take a turn at defining the import of a contest.  Proposed press release:

To:  Interested Parties

From: Obama For President Campaign

Re:  May 6 North Carolina Primary

If Hillary Clinton cannot win the support of voters in an important state like North Carolina, the vialbility of her candidacy must be questioned. 

North Carolina could have carried Democrats to victory in 2000 and 2004.  It is the home state of prominent Democrat John Edwards and is an increasingly significant state in the political arena.