this stuff is, you know, witness dependent and it may be that if this is a new tale that cohen is saying -- remember, cohen hasn't spoken to mueller -- that it is something that mueller will now start running down. so we don't know yet whether he's looked into all of this. >> so listen to what cnn legal analyst paul callan is floating out there. i'm going to read a part of his cnn.com piece. he writes, "if cohen's claim is corroborated, it could theoretically give special counsel robert mueller the leverage to propose a deal. resign the presidency in exchange for immunity for don junior. otherwise, don junior will be indicted for lying to the senate judiciary committee." rachel, what's your take? >> first of all, i think that's really problematic for a couple of reasons. you know, do we really want -- understanding that someone's unpopular but there's a constitutional process for how an impeachment, how someone becomes removed from the presidency to let someone in a position of robert mueller decide who the president is at