Sanders is not just another Democrat - he's a radical, a Socialist, as woke as they come. He's AOC, he brings all the culture war baggage that costs Dems swing votes.
Americans really don't want to get with Democratic woke pc campus politics.
Americans are fine with Dem economics and the like, but not the focus on PC issues.
When the GOP slime machine finally starts working against Sanders it's going to be horrible.
Right now the GOP is supporting Sanders - they desperately want him to be the nominee. That will change and the oppo file is immense.