Missing data, or a missing prediction…since the chart is showing a difference between the two. It’s possible the model for those areas had some issue. I agree it’s worth questioning.

50% lethality in humans, not wildlife

There’s no simple answer to your question, just like there’s no quick solution to the problem of inequality. But one premise you’ve mentioned isn’t quite correct. The democratic party hasn’t really been “ruling” for most of that time. They’ve controlled the presidency, yes. But for all except 2 years, they haven’t controlled Congress (it’s been either divided or republican controlled), and they haven’t controlled the supreme court. That said, a lot of Democrats are still happy to push the status quo, and there’s plenty of warranted criticism to go around.