I found it very interesting, my friend. As I thought about it, though, I'm not surprised. There are two things that account for this, in my view:
First, most of the South is coastal. It is more dynamic (people moving in), physically closer to the Northeast than the Midwest, and more involved in international trade. It has more of a migrant population, too. The urban-rural population divide leans urban (Atlanta, Miami, Nashville, Memphis, etc.) The skew is the rural- urban ratio, and the fulcrum is the suburbs. The more and bigger the suburbs, the weaker the GOP gets (think Virginia and Johnson County Kansas, suburbs of KC, where Sharice Davids won).
Second - and remember, I'm a native Missourian - Midwesterners are extremely stubborn people. They come from pioneer stock, and stay set in their ways much longer. If you were to break down those survey results further, you would find a stark difference between the rural and urban areas of those representative States (and elsewhere in the country, too). In the rural Midwest, preachers hold sway. Radio personalities like Hannity, Limbaugh, Erickson, are just the modern equivalents of old time "revivalists". They just don't travel to the communities they preach to. There's a distinction between the bible belt and the rust belt, too.
Trump will remain strong with "believers", but industrial workers are skeptics. They went with him in '16 because they were skeptical of the establishment. But, now HE'S the establishment, and they haven't got what THEY were going for. They may not vote for dems, but they're more likely, like you, to "sit this one out".