I have no idea what that chart means, other than some states are being incrementally changed from red to blue by the *millions* of their OWN young people graduating from these leftist government run indoctrination centers every single year.
I’d guess in nearly every state, probably a million + are being released from public schools and many of them start voting in the years following. Hence, the incremental changes. Now compare that to how many actually move to your state from say, CA. I can assure you, that number don’t even come close to the number of little leftist graduating each and every year from the liberal public school systems.
Don’t be so hard on yourself, you will figure out charts and click on articles.
Mass migration to such states is changing the demographics, especially the via the cities.