he is not up for it. this story really puts his family under the microscope. >> absolutely. now that we see elizabeth warren at least in the new -- the most latest des moines register poll announced she is the frontrunner in iowa. she clearly has momentum right now. if you are joe biden you have got to be nervous the fact that you are out here on this and so is your son. >> they are the center of the story. in way around it. whether cnn admits it. great to see you tonight. >> thank you, tucker. >> tucker: joe biden is at the center of this story. in 2016 he told ukraine to fire the prosecutor overseeing a investigation involving his son's company. now biden says the whole matter is worth impeaching the president over. >> the president should stop stonewalling. this investigation and all the other investigations into his alleged wrongdoing. using its full constitutional authority congress should demand the information it has a legal right to see. if the president does not comply with...