If you want to give underdogs a chance, the following criteria should apply:
My picks for southern states would Arkansas by quite a margin, Tennessee, North Carolina. My specific objection to South Carolina is that as a state it skews extremely Republican.
They did this after Carter won, they wanted to keep out anyone who could surge on their own power. The democratic party is making a fatal mistake: they are weaker than they think. Just because the GOP are slime doesn't mean they are easily going to waltz in and take over, I promise you.
The longer the primary season, the more Free and UNFILTERED Media our team gets.
There should be two weeks between IA and NH, and two weeks before the next contests. John Kerry ran the table because of the front loaded process, and he was the worse for it. If he had won after a longer process, he would have been forced to develop a real message that would resonate with a diverse group of voters. As it was, he rode the electability pony to the nomination, and never bothered to craft a viable general election strategy.
Stretch out the Primary Season -- and we ALL win.
But avoid states where big TV markets dominate at first because candidates with a lot of money immediately become the favorite there. Or (gasp) actually limit the amount of money candidates can spend on advertising but not other campaign expenditures like events, travel, etc.
In any case, there's no coincidence that the only two successful Democrats to win the Presidency after Nixon implemented the Southern Strategy were Carter and Clinton. Both men enjoyed crazy, elongated primary seasons against an incumbent who didn't take them as seriously. Hopefully the Democrats will win again for a reason other than this...but it bears keeping in mind.