It’s not purely proportional.
It’s winner take all by district, 3 for each of the 53 districts for 159, and 11 awarded for winning the overall popular vote, and 3 super delegates that every state gets.
Which means Huckabee won’t get any, he’s polling at 10% and will not win any district out right. Romney should be able to win 20-25 districts and end up with around 70 delegates based on these numbers, and he could conceivably do better than that.
Come on California.