What the 35 year poll shows is the trend from Conservative thinking base, to liberal thinking base John. The general acceptability of issues and lifestyles is evolving. Think of the times, where the 60's and Viet Nam era mindset was very conservative Growing up in a post WW2 mindset of our parents. My generation was treated that if you would not serve your country, you were a coward, a very stringent conservative thinking. But my generation learned, those conservative ideas were not all so admirable, in terms of issues like civil rights, sending our boys off to war, and other social stigmas. Then we had Watergate, where people got real sick of being told what was right and wrong, when the President was the worst of all. Now these kids of a totally Conservative upbringing, were beginning to be the young and 30 something heart of america, having kids, and believing in a free way of thinking. Why Not we all said! Many issues evolved like woman's equality, abortion, the Death Penalty, and many issues that created a conflict between our laws and personal beliefs.Nothing was wrong with drugs and a free lifestyle, anything goes.
How many cases ended up in courts just because the non smokers were violated by smokers and second hand smoke, seeing the issue as a "rights violations". Conflicts between rights like the right to believe in God, vs those who do not, and court cases pitting the two ends of the spectrum at odds. Within those 35 years of your poll, issues like gays coming out of the closet, teen suicides as a result, and even transsexual issues, have all become very much on the surface, no longer hidden from society. The gay rights issues is one of those issues where for generations it was kept under wraps, as were many private issues.
As times change, so does the rolls of our elected officials, and court appointed judges consequently. The more liberal based voters in States like California, vote in more liberal politicians, who appoint more liberal viewing judges to the higher courts. the trend has moved to much more liberal mindsets in our states, compared to other states who are staunchly still ultra Conservative. The balance of power shifts in our system, in elected offices they have short terms, but in our higher courts, they are appointed for long periods, so the swing of the higher courts is a slow process.