history is very clear about dems candidates who run to the left at the national level or in close competitive states/districts. they lose.

presidential elections are won in the middle. especially for democrats.

bernie would have performed worse than hillary among moderates. and black people. and latinos. and urban voters. and suburban voters.

thats the entire ballgame right there for democratic party candidates.

people had this romanticized daydream of him possibly winning over white working class voters who voted for trump. but he split the wwc with clinton almost evenly. and even if he did marginally better with them...he would have done significantly worse than everyone else.

bernie would have had a demographically contracted coalition of voters compared to obama/clinton(h). in no realistic world does that amount to a victory.