Rep. Bennie Thompson argues the House Democratic Caucus should consider rules factoring in the expected loss of Black Democrats representing Southern states in the upcoming midterms. Mark Schiefelbein/APHouse Democrats face a conundrum — they are optimistic about retaking the majority in the midterms, but with redistricting reshuffling the map it means Southern lawmakers’ power will be greatly diminished.Bracing for the loss of some of their col…