Come on man, Bernie’s whole schtick is “not me, us” as he implores all people from all walks of life to come together. That’s what real unity is, not shaming people out of addressing substantial policy differences or politician’s records. Bernie is so anti-antagonism that he literally told people to stop talking about Hillary’s emails in 2016 and runs no oppo whatsoever, even when his opponents are spending millions to smear him.
Even with the recent attacks from Hillary and Warren, which are really anti-unity, if you’re concerned about that, Bernie responded very gracefully if he acknowledged them at all, when he really could have let them have it. The idea that Bernie is uniquely aggressive is not only flat our preposterous, it belies a massive misunderstanding on the part of anyone out of touch enough to claim too exists.
If we nominate another neoliberal they will not beat Trump. And even if they do, the backlash will be swift and fierce — it is in that scenario that we get an even worse far-right ideologue as you mention. Obama failed and it got us Trump. Blair failed and it got us May/Johnson. Macron is failing and very nearly got us Le Pen. So on and so forth.
Republicans know that Bernie will be hard to beat, and everyone from Trump to Carlson to Republican strategists are admitting this. Anything else is clearly misdirection. Trump just tweeted out a poll that shows him beating every other Democrat but Bernie. Wonder why he left him out!
Bernie’s ability to work across the aisle and get stuff done is well-documented, and even notoriously center-right PolitiFact rates this as fully True. Republicans will try to obstruct everything, but they actually respect Bernie, unlike how they hated Obama and Hillary. ACA was moderate and they didn’t make it easier to pass because it was moderate. Medicare for All will also be difficult to pass, but at least that will excite people and have a mandate of the masses behind it to help push it through!
Here are more sources on how Bernie plans to get things done. Imagine how much of a hero he will be when he actually gets the progressive policies he runs on passed instead of selling out immediately like Obama did. Think FDR.