if there was an acceptable younger candidate available today, we would just support that younger candidate.
it's not clear to me why we should put faith in the universe to produce a better candidate in the next 6 years.
and, if we are in the same position four years from now, the same logic will hold: sanders will still remain the candidate, by default.
i lean in the opposite direction: i think they should abolish term limits.
https://theintercept.com/2019/02/22/bernie-sanders-2020-one-term-pledge/