Honestly I think Trump would have labeled him "3-home Bernie"[0] or something and sunk him, similar to how he sunk Warren (w/ the Pocahontas meme). Don't get me wrong, Bernie is my favorite, but no one is immune to Trump's attacks, and there is just no way to attack him back (in a way that his supports care about).
[0] https://heavy.com/news/2019/06/bernie-sanders-house-home-pho...