Maybe because voting demographics change so slowly, policy changes slowly too. Thirty years ago, when I was still in K-12 school, Baby Boomers were the largest generational voting bloc in the USA, and they still are. With a few exceptions that the rest of us are grateful for, it's been politically status-quo for pretty much my entire life.

Right, but I think you are making my point. Despite the boomers dominating for decades, we’ve seen the GOP swing far right relative to the 70s/80s. For example, Nixon massively expanded the Clean Air Act and enacted the Clean Water Act, which never would never have happened with the GOP in the last 30 years.