Bernie might be smarter than Biden. He's definitely a better talker (which isn't saying much). But he still can't beat Biden.
That's because Biden has better looks. It may seem improper, but in American elections, looks really counts, when the votes are tabulated. They are both about the same age, but Bernie looks OLD enough to be Biden's father.
It depends on his outcome in the next debate. I watched Harris go from the top candidate, to "yesterdays news" in one crushing monologue from Gabbard.
I watched Biden rise from the ashes just by default. By winning S Carolina.
The debate will be watched by every undecided. The fact that they are sitting might raise the question from the moderators. You know Trump won't allow that. He will either agree to it or just say, "no, we stand for the American people" and put the heat on. When it comes to Game Theory, Trump gets it.
So, I do think Bernie can change a few minds, only if he goes for the jugular though as Gabbard did. If he has a nice hot cup of cocoa and treats the next debate like a chat with the loyal volunteers at the local YMCA, he will be in a tough spot.
I prefer Biden compared to Bernies policies (clearly), but, I think Trumps chances improve if these two duke it out. Though, if Bernie dropped out very early, Bernies Bros might be VERY angry and vote Trump in even higher numbers than if he fought it out to the end.