If Senator Sanders really loves his country, he will bow out.
A person in his physical condition (not to mention his age) should not be subjecting himself to the rigors of campaigning next year.
It is time for him to pack it in -- for the sake of his loved ones and the nation.
If he doesn't and actually wins the nomination, all eyes will NOT be on him but on his Vice Presidential selection.
Senator Sanders loves himself. He is an opportunist, and a vacuous populist whose political career has amounted to virtually nothing. Always pumping his chest that he is an "independent" but joining the very party whose rules he criticizes, when it is convenient for him, in order to run for president. If you doesn't know it, he left the party again after the end of the 2016 campaign... then joined again for 2020. He kept running in 2016 past the point when his candidacy was viable, and kept accepting campaign donations even after that point was passed.
He criticized Hillary for corporate donations... when he also accepted donations from corporations (only, they were further down in his list of top donors, simply because he sucked at corporate fundraising, not because of principle, otherwise he would simply refuse those donations).
He criticized the Democratic Party superdelegate system at all turns of the campaign (a system of a party he signed up for, and promised to abide by that party's rules, the same rules he was very aware of when he signed up), saying that popular vote should prevail over the superdelegate system. That was before he got way behind Hillary by the millions, in the popular vote. Then he turned around and said that the superdelegates should vote for him over the popular vote, because according to him he had better odds of beating Trump. That's what is called hypocrisy.
By the way, the supposed better odds came from polls of a hypothetical scenario that was unrealistic since at that time he couldn't win the nomination, and the only reason those poll numbers were there was because he had never been properly attacked by the Hillary campaign (afraid she'd need his supporters later) or the Trump campaign (delighted that he was damaging the more viable candidate). His popularity numbers would have dropped once the campaign attacks started, exposing his many weaknesses. That was never necessary, because he lost, BOTH the popular vote, and the delegate vote. Even without the superdelegate system, he would have lost, too.
So, Bernie Sanders, once truly and thoroughly defeated (the loser), went through the move of apparently supporting Hillary... too little too late. He created the Bernie or Bust phenomenon which ended up hurting the Democratic chances.
Bernie was one of the important factors (not the only one or even the most important one, but definitely, one of them) in securing Trump's victory. That's a spoiler role. That's how much he "loves the country." If Bernie had dropped out a couple of months earlier and energetically fought off the Bernie or Bust movement, most likely we wouldn't have Trump as president. Given how close the election was (decided by a total of 80,000 votes in 3 states), each and every one of the important factors (the main one, Hillary's incompetence and unforced errors, and all the others, Comey's letter, the Russians, the hackers, racism and xenophobia, etc.) would have prevented Trump's victory if they did not happen. That DOES include one loser Senator from Vermont called Bernie Sanders. Without Bernie Sanders we wouldn't have Trump, just like without Comey's letter we wouldn't have Trump, etc.). He is not the only one to blame, but he definitely shares part of the blame.
Bernie is nothing more than a failed narcissist. He is a loser, and will lose again this time. The sooner that loser drops off, the better.