The answer to the first question is easy- "yes" or if not yes outright, certainly among the most. The South (and in particular, the Deep South), is the most inelastic region in the country, with FL as the only exception. If it's not MS, then maybe AL? But we're splitting hairs at that point.
The second question is also relatively easy- trending D long-term and it's pretty obvious. NC Yankee has the correct analysis here, although one quibble- 2028 (even with an Obama type) seems optimistic.
TTimmy, I don't think the brain drain issue (let's assume it continues) will have much an effect. White millennials leaving will just be overwhelmed by White seniors dying off (of which there are more by the way), and the net effect is at best, zero. Even if migration out is particularly severe (which is not unrealistic, MS is almost last in growth nation-wide, at 0.6%, and had a -4% growth of millennials over the past decade), I think that maybe just delays the inevitable by a decade or so. Although you do have a point, and it's one reason why I think 2028 is a little too soon.
The only thing that will keep MS from flipping D eventually is if the black vote dramatically changes, and I don't think just a little depolarization would do it TTimmy. Basically the black vote would have to essentially flip parties and start voting R... and while I won't say it will never happen, it's the sorta thing that would require a significant and unpredictable national black-swan type event.
By the 2030s or 40s, some less sophisticated political analysts will be scratching their heads and saying.. well gee, how in the world did MS ever flip. When really, it was always pretty obvious. The same thing will be said for ME (the counter-part to MS, in some ways, right up to the anemic growth), when in a few decades it is likely to be one of the most Republican states in the country. ME will flip way before MS though, in fact, it's already happening as we speak.
Maine is going to become one of the most Republican states in the country? doubt.