elizabeth warren anand bernie sanders clear they are not going in on personality. we saw them on key issues such as health care. joe biden is a centrist figure who can appeal to middle america. elizabeth warren wants to see big, structural changes. some clash moments. 77.biden is he would be 78 by the time he becomes president if he gets the candidacy. he has fallen under criticism for mixing up the names of towns there have been mass shootings in. one candidate played into that. questioning joe biden's memory and it came to the health care debate. >> you just set a few minutes ago they would have to in -- they would have to buy in. are you forgetting already what you said to minute ago? you have the record player on at night. make sure the kids here words. of that clip part was from later in the debate. he made comments which have been media, mayn s social be just a slip up, but people questioning whether he could be in touch with the younger generation. this popointbest at to take on donald trump? >> if you look at the polling these figures i have pulled up, joe b