The SCOTUS did not rule on that kjam. If the SCOTUS had heard it I am confident that the SCOTUS would have ruled that because it reflects the history of the community, that it would be constitutionally permissible to recognize that history in the seal.
You may be correct that the LA county may not win this at the 9th circuit since the 9th Circuit worships at the altar of Satan himself. But the SCOTUS has overruled the 9th on almost every major constitutional question that has been brought before them in the last 20 years.
LA county does not want to spend the resources to take this to the Supreme Court. In essence they are cowards.
Well.. your'e right the SC didn't "rule". It was worse than that... they didn't even listen. It wasn't even close enough in thier minds to get a hearing in the court. They rejected the cities claim without even listening. That's worse than losing in court.
This is a red herring, in that several law firms have offered to do this pro bono.