The subtext of this article seems to suggest that Hillary Clinton will be the next US president, but that after her, a slightly younger candidate who shares Bernie's views might stand a chance. If, in eight years, current Bernie supporters then represent the majority of Democrats under sixty, I can't see any way that the Democratic nominee won't share many of Bernie's views. But that all assumes that the political landscape won't change significantly in eight years.
It seems to me that we are in a realignment period. The republicans are incredibly fragmented between Trump, big business, and hating gay people, and the democrats are obviously split in half between the establishment and the progressives. It will be interesting to see what, if anything, happens in the House and Senate. If the republicans stagnate, I could see potentially twenty to twenty four years of consecutive Democrat presidents, but I don't know if that's going to happen or not. If social progress advances enough that the Republicans can't rely on LGBT bashing or Islamophobia to bolster their regressive economic policies, they might be forced to actually try to develop a new platform. I can't imagine what the platform would look like, but I also can't imagine that the republicans think that what they have now is working for them.