When Edwards bowed out, there was an argument in favor of him staying in – even tho he looked to get no better than 15% of the vote in most states. The idea was that he would rack up a solid little share of delegates (+24 when he quit) and use it to be influential (in terms of the platform, etc ) at the convention. The same logic applies about 1750 delegates more for Hillary.

Other than that, I'm amazed by the durability of Hillary's support. Most candidates lose vote when they are perceived as less likely to win.
but generally, you are right to be more interested in Cain.