California is a proportional delegate state (the correct google incantation to figure this out is "proportional delegate states" - I then followed the NYT links.) Furthermore, it is skewed towards splitting delegates evenly. Districts have 3-7 delegates possible, and districts with precisely four delegates are going to split 2-2 unless one candidate gets about 2/3 of the vote in that district. Apparently this caused candidates to concentrate on districts with an odd number of candidates (I presume the 6 candidate case has a weaker version of the split problem, though I didn't see that explicitly.)

So Clinton's 10 point victory in California is going to end up somewhat muted in delegate representation.