Sanders never faced any GOP attacks, had virtually no minority support, and his candidates and platform underperformed Clinton. Evidence suggests he’d have lost badly
No evidence suggests that at all, and its wholly unscientific to claim otherwise. The only evidence we have about how Sanders would have performed against Trump is precisely the polling that I already linked. His advantage in the polls included an overwhelming amount of minority support, so I don’t know where you are getting ideas to the contrary.
Regarding the GOP attacks, consider the lack of logic behind what you just said. Clinton, toward the end of the Democratic primary, was entering the general election with about a 3 point advantage. Sanders would have been entering with an 11 point advantage. If you happen to believe GOP attacks make any difference at all (and, given Clinton’s popular vote win, there is no evidence to believe that assertion), we’re talking about attacks that need to erode an 11 point advantage as opposed to just a 3 point advantage. Even by your own argument, Sanders would, according to all available evidence and inductive logic, have had a much better chance to beat Trump.
You really just need to ask yourself the question: do you want the Democrats to win or lose? If you want them to lose, your strategy of ignoring the youth vote works, because they really are the future of the party. If you want the Democrats to win, you should consider asking the Democratic Party to adopt a platform that will appeal to younger voters the way Sander’s platform appealed to them. It’s really that simple, because that element of the Democratic Party will represent a greater proportion of the voters next time around.
It is wholly illogical to try to defend a platform and strategy that just lost to a repugnant oaf who is among the worst presidential candidates in American history, and that lost ground in state legislatures around the country, and in Congress. The Democratic Party and it’s terrible platform epic failed in this election, but that’s what they get for ignoring their base, and it’s only going to get worse if they keep ignoring their base.