"But what if the political left starts behaving like the political right, making support for implausible claims a litmus test of loyalty, declaring that anyone raising hard questions is ipso facto corrupt? That would become very uncomfortable, to say the least.
It’s also, almost surely, a losing game in the end. If it comes down to gut feelings that reject hard thinking, the right is always going to have an advantage.
So I hope that the Sanders campaign doesn’t just brush off this criticism as the “establishment” doing its corrupt thing, and realizes that it really is in danger of losing not just an election but an important part of what it should be standing for."