enth older. why isn't he being criticized? >> that time may come. you've got a president in his 70s, joe biden is the frontrunner and elizabeth warren is on his heels. i think in a sense part of the problem for bernie sanders is i don't think people think he is a frontrunner right now. maybe it would be good for bernie sanders if people were asking about his fitness because that would imply they thought he might be the nominee or might become president. i would say one thing, i think that the key here is to exhibit fitness, right? you can put out your medical reports, but the key is to demonstrate, mott s demonstrate, not say you're healthy, but demonstrate it, being quick witted. elizabeth warren is demonstrating she will be a young 70. >> this new round of questions about biden's mental fitness