That is the core distinction between the two world views. One is based on logic and facts, the other on emotions and wishes.
Remind your son that emotions are in the subconscious and thinking is in the conscious part of the brain.
Age 30 is time to start relying the higher level functions of the brain. At least, this is what I tell my 30 year old son, who has been subjected to left coast radicalism all his life, except for his contacts with his parents!
My son is also West Coast. He is in LA and starting to have second thoughts about a lot of his "Foundation blocks of beliefs. It is hard to give up on a belief held so strongly. When he comes around to rational (logical) thought; the conversion will be all that much stronger.