washington pastor mark burn prominent supporter republican presidential nominee donald trump apologize tuesday send tweet show cartoon image democratic nominee hillary clinton blackface burn african-american frequently one warmup speakers trump rally send tweet monday bolster trump campaign contention clinton pander black vote ignore community elect nov. ways pander african americans cartoon image say tweet emerge time trump try broaden appeal african-american voters say want create job make black neighborhoods safe people walk street without get shoot burn begin take fire tweet delete apologize image message sorry offensive blackface image hillaryclinton stand message black use dems vote burn say trump booster apologize clinton 'blackface tweet