I know it's really fun for us to watch the primary results trickle in week by week state by state, but wouldn't the best solution for a representative primary just be holding it nationwide all on the same day?
No state is more representative of the country than all fifty of them
A national primary day would benefit candidates with more money/campaign infrastructure at the expense of those with less. Gradually narrowing the field down is better, but in an ideal world, the states would rotate. Spin a wheel, even.
But Democrats should go with Mississippi if they want an early state with a heavily black population. Unlike South Carolina, trends actually favor Democrats long-term in Mississippi and the state party isn't full of lunatics and grifters.