Because of the Voting Rights Act that requires districts be drawn explicitly for Black voters, that’s why.
If I were to be honest, the way my CD is drawn, it is probably set up to keep it R. It is primarily the “white” areas of Tallahassee and goes south to the Gulf covering the rural areas down to Panama City and southeast taking in the rural areas along the Gulf to Dixie County. From West to East, it’s 240 miles ending just North of the Tampa suburbs. D-5 is primarily Gadsden County to the Georgia line and the “black” and college areas of Tallahassee. Gadsden County, interestingly enough, is the only “minority majority” county in the state.