Thank (Blame) adopted son, Ronald Reagan, who condemned it to inevitable Democrat one-party tyranny with his Apocalyptic 1986 Amnesty, thus giving the globalist RINOs the excuse to further that betrayal in perpetuity.
California - which produced four presidential terms of native son Richard Nixon and Ronald Reagan - was once more generally and more consistently conservative than always heavily Democrat Texas ever was - which state produced the evil political machine, and eventual “Great Society” Presidency, of Democrat Lyndon Johnson long ago. (Shall we all join together in condemning all of Texas for that enduringly corruptive legacy?)
California is now what you say. It was not that in the past, during my lifetime. Hollywood and San Francisco were once the outliers.
Obviously, you can "blame" whoever you care to, for current conditions in the PRC [Peoples Republic of California]. I believe that most people would blame a rather large collection of self-described 'progressives', left-wing activists and politicians...