First, they did that with Hillary, then with Biden. So poor Bernie has been left out in the cold twice, three times if you count Biden's inauguration. No wonder he looked unhappy!
But wait, what about 2024?
The website below has the posters that make the Bernie Bros smile:
Bernie 2024 Poster
https://www.redbubble.com/i/poster/Bernie-2024-by-boxsmash/46624929.LVTDI
Just imagine this 2024 scenario:
The Democrats run Kamala Harris after the untimely and covid related (of course) death of President Biden. He survived his first two covid shots, but a subsequent "booster" finally got him.
The Republicans decide to run their previously anointed choice from 2016, Jeb Bush. If the sprightly Jeb were to run in 2024, he'd only be 71 and thus the youngest man in the race.
Just to make things interesting, Bernie Sanders could revive the old democratic socialist Liberty Union party. That was his party when he ran for governor of Vermont back in 1971.
As for Trump, he could start his own Patriot Party with the 74 million plus who voted him eager to join it.
Who would win?
That would depend on who counted the votes and how they were counted.