Bernie's never running again period. He's just too old at this point to be a viable candidate in 2024, and the chances are that whoever wins now will get a second term - especially if military conflict with ISIS (or, god forbid, Russia) were to erupt during the first term.
If Bernie wants to run again at that age, though, I would love to see him still involved. If Clinton wins, our country might be more ready to move further left at that point. If Trump wins, then of course there's a chance that popular opinion sways back left by the end of his term(s) as well. I wouldn't be opposed to him coming back, I would just worry for his health.
Warren will be about the same age then as he is now, though...
but it still counts Nevada as a swing state 
