Yeah something there doesn’t seem to add up.  Asian-Americans are a pretty big group in California and Abromowitz doesn’t mention them, but it seems like even if Bernie was winning handily among Asian-Americans (which other polls aren’t showing anyway), and other smaller groups (Native Americans, multi-racial follks), it would be hard to see how that would be enough to make up the difference.
ETA:  As far as today’s NBC/WSJ/Marist poll, it also shows Hillary leading Bernie by a larger margin among whites (51-46) than she leads overall (49-47).  And it shows Bernie with a modest (within the MOE) lead among Hispanics.  The rest of the demographics seem pretty familiar:
In the Democratic horserace, Clinton leads Sanders among likely voters ages 45 and older (63 percent to 33 percent), self-identified Democrats (57 percent to 40 percent), women (54 percent to 41 percent), past Democratic primary voters (53 percent to 42 percent) and whites (51 percent to 46 percent).
Clinton also is ahead among those who have already voted, 58 percent to 41 percent.
Meanwhile, Sanders leads among first-time participants (72 percent to 28 percent), independents (68 percent to 26 percent), those younger than 45 (66 percent to 30 percent), men (54 percent to 43 percent) and Latinos (49 percent to 46 percent).
So, of course it’s possible that the poll is just way off, and Hillary is actually leading among Hispanics.  Though there is also a fairly plausible explanation for why Bernie may be leading Hillary among Hispanics in California – they tend to be on the young side, and Bernie has done well among younger Hispanics (as he has among younger voters in general).
Will be interesting to see what the Field Poll says, as it’s often described as the “Gold Standard” of California polls.  I believe the latest Field Poll (and I assume the last one of this primary season) comes out tomorrow.
My guess is California will be close, but if I had to bet I would still bet on at least a narrow win by Hillary, given the “semi-closed” type of primary, and the large number of folks who vote early, by mail.