That has certainly happened before but Bernie couldn't even beat a terrible candidate like Hillary, do you really expect him to beat a great candidate like Trump? His is not a unifier and he didn't get out the youth vote in big enough numbers. Some of us fondly remember George McGovern but don't want history to repeat itself.*YAWN* How many of these threads will we be subjected to? The Killer Bs(Bernie & Biden) must be gaining some traction and it's showing in the desperation of the Trumpkins.
Trump will dismantle Biden. Bernie is the only one that even stands a chance. It's worth noting that Michael Moore (the lefty that predicted Trump's win before ANYBODY else) thinks if the Democrats vote with fear and go with what they think is safe they will definitely lose to Donald Trump.