clear. the argument from the biden campaign of course will be donald trump will get our voters out to the poll, it's very clear. but the risk of the electability argument it puts that much more of a focus on yourjoe biden is . there is perhaps more of a tolerance for gaffes, for the missteps. that's part of the joe biden appeal. >> then that's the debate statement which is the next big test for all of them on september 12th. all of them who qualify. castro has met the mark. >> and we may be down to one stage which makes all the difference. you know, castro's presence is an interesting one because he's shown he can take advantage of the moments. how, i'm most interested in seeing warren and biden on the same stage for the exact same reason that mike points out.