I was referencing that website, it kinda lines up around the time the parties switched. The party switch could be another result or part of the cause of that inflection point. I realized there could be connection when I was trying to figure out when the parties switched, but I don’t know enough about that history.
Assuming only red states have low population and grows faster is weird, but might be plausible. I could look into historical birth rates of each state, or population changes, comparing them to each other to see if the trends make sense. I assumed (or didn’t think of) there wouldn’t be bias growth rates based on state affiliation (red or blue). My first thought was gerrymandering and could it cause this bias. Either way, I didn’t think about population growth having an inherent bias in this.