siraj hasmi and julian zeleny. is the author after new book "fault lines, the history of the united states since 1974." siraj, is this kind of trash talk you'd expect from donald trump a year out from his general election, from the re-election campaign? or is this an indication that this is someone he is concerned about? >> well, the thing is that joe biden is leading in the democratic field at the moment. of course, we are more than a year out from the 2020 presidential election. and what is interesting here is that donald trump, with respect to this government shutdown, if he does not cave -- i should say if he does not declare a national emergency and he caves on state funding for the border wall, then he has to start worrying about a 2020 presidential election in terms of which democrat he faces because any of them could probably defeat him because his base would be fractured at that point. biden of the democratic candidates who are, you know, flirting with running or announced they are running, he is the most