Right, but DOMA states, "No
state (or other
political subdivision within the United States) needs to treat a relationship between persons of the same sex as a
marriage, even if the relationship is considered a marriage in another state."
That being said, how can it be said that what California did is unconstitutional without also bringing up the fact that DOMA is? Because to say that California's actions were unconstitutional is the very same as saying that DOMA is wrong. Because then the ruling is basically saying that a state does have to treat relationships between persons of the same sex as marriage.
If it doesn't directly affect DOMA, it would certainly allow for judicial pressure to get DOMA challenged in court.