Michael B. Moore sat down, closed his eyes and lowered his head. The pastor standing behind him clamped his palm on Moore’s shoulder, and three women rested their hands on his back and arms. They sang, prayed and shouted “Hallelujah!” They gave their blessings knowing that the political road ahead would be difficult for Moore, a great-great-grandson of a Civil War hero who commandeered a Confederate steamer to escape slavery before serving five terms in Congress. Moore, 61, hopes to follow...