comments and also the "wall street journal" breaking story about the ukraine phone call with president trump. take a listen to biden. >> wait a second. wait a second. not one single credible outlet has begin any credibility to his assertion. not one single one. and so i have no comment except the president should start to be president. >> all right. let's chew over all of this. your response? >> hey, if you are leading in the democratic primary because people think you're the guy who can take on donald trump, you want to be attacked by donald trump. and i think he did fine. >> i would worry if i were a biden supporter this is waving a red flag at the trump folks and that what happens is it wouldn't -- it wouldn't be because they don't think anything is there but because he is not going to be well-positioned to combat donald trump. >> but then in the context of what is happening today, being attacked and having a back and forth with trump in the couple of days about this, this is good