Laguna is an art colony. It has been that way for a while, and has many galleries, stores, and shows like
Pageant of the Masters have self-selected the limousine Liberal types even before that entered out lexicon.
Newport meanwhile has encouraged self-selection by the 'conspicuously wealthy.' The harbor and inlets offer many waterfront properties, and the gradual elevation increase offers many more ocean-view homes. The harbor especially now offers ample space for private boats like certain parts of coastal Florida. The concentration of money has brought with it the associated stores: Fashion Island is a truly massive semi-outdoor mall built during the heydays of suburbanization, the coast highway is lined with Luxury Car dealerships, you get the idea. Even ignoring the fact that Southern California White voters are still republican overall, just usually outvoted by other groups, this is a place that attracts the more GOP-leaning new-money and pushes away the old-money.