I wouldn’t be surprised if we never see another Democrat Governor of Louisiana in this century.
I wouldn't go that far. In the American system, governor is by far the easiest thing for the "wrong" party to win.
We’re going on over 40 years of one party rule in about half a dozen states, and that includes time periods where the minority party won some Senate races and other statewide races back in the 1980’s through mid-2000s. That era is gone and is showing no signs of a renaissance unfortunately.
If you include 25+ years of continuous party rule, the list gets to almost half the states.