so we've seen now elizabeth warren make strides on electability and next look for does elizabeth warren or other candidates make some strides into those biden groups, african-americans, older voters and those moderate conservative democrats. >> interesting. david chalian, thanks. let's chew over this. karen, if your advising bernie sanders or elizabeth warren, what would you tell them given this poll. >> i would tell them keep making the argument that you are the person that could beat trump because that is the most important thing to democratic voters. the next several months across the fall and various debates, this is your best opportunity in front of the national audience to make your case why you're the one. and certainly for warren it is really interesting to see that movement because as much as i hate to say it, for women candidates and when you're running for executive office, it is a lot harder to make that case. >> very interesting that biden has gone down in the electability view among democrats and warren has gone up. why do you think that is? >> not surprising.