on cbs, president obama said he understands why biden might get in. >> if you're sitting right next to the president in every meeting and wrestling with these issues, i'm sure that for him he's saying to himself, i can do a really good job. >> you can see why the poll numbers in this new poll particularly in south carolina really plays towards hillary clinton's advantage but also why her camp is so concerned about what joe biden is going to decide. she gets at this point 59% of the crucial black vote in south carolina. you pull joe biden out of the race and pops all the way up, wolf, to 84% of the black vote she gets compared to bernie sanders. it's no contest. >> he's not well-known. much better in new hampshire. all right. brianna, thanks very much. let's get more on the political drama that will unfold tomorrow night. john berman is with us. you've been doing reporting.