they knew this would be a disaster coming down the pike. >> we've got to take a break. appreciate you guys being on. thank you. just ahead, the watchdog group christine o'donnell is threatening to sue, what do they have to say about her claims of libel. let us know what you think. live chat is happening. ac360.com. also ahead, her challenger, chris coons caught up in a controversy of his own, words he wrote a quarter century ago about being a bearded marxist. those two words are being used against him. we check the record. and sanjay gupta, this little girl battling an unknown killer. tonight kylie's parents continue their desperate search for a diagnosis. >> i feel like a bad parent. why can't i help my kid? >> can't really put it into words. just helpless. have made me, rich and hearty.