In your example, 60% of people didn’t support gay marriage in 2005. I would argue that gay marriage didn’t become a “better” idea between 2005 and 2015. It was always a good idea that provided tangible benefits to gay people, public opinion didn’t just reflect this.
This is sort of aimed at other comments in this discussion, which seemed to be lamenting that the “polarizing” ideas were being pushed in people. I don’t really care if something like, say, a “bathroom bill” is considered a polarizing culture war issue or how many people support it. It has an effect on me and the other trans people in my life, and I don’t feel any inclination to compromise on my position
