elrod, hillary clinton's 2016 campaign, also an msnbc contributor. matt, you've got some solid new reporting about the concerns that some of biden's supporters have about how his campaign is handling the situation so far. walk us through what you've learned. >> so there is growing concern, i think, among his allies that biden faces a dramatically different race than he did a week or two ago. he's having to run a general election against president trump at the same time he has a very feisty democratic primary challenge at the moment and his allies are worried about how he'll handle that. he can't lose sight of elizabeth warren, eclipsing him from some polling. and at the same time on a daily or an hourly basis president trump and his allies are focused on biden, and some in his orbit want a little bit more of an aggressive posture than he's taken so far. >> what do we know about this letter reportedly sent by