You’d have thought she had thrown Bernie Sanders to his death from a tower of million-dollar bills.

Actually, what film director Ava DuVernay tweeted on Saturday was just a mild rebuke: “I’m undecided. But I know this isn’t what I want.” She was responding to a Sanders tweet warning the Democratic and Republican establishments that “They can’t stop us.”

In response to her response, a digital mob numbering in the thousands descended upon DuVernay. Many contented themselves with noting how “surprised” and “disappointed” they were at her failure to appreciate the senator’s wonderfulness. Others went below and beyond, calling her “bitch” and, more insulting, “right winger.” There were isolated death threats.

It was just the latest example of the swarming behavior that, in many minds, characterizes Sanders’ voters. Not that any candidate has a monopoly on overheated or bullying supporters, but as many observers have pointed out, his people seem — and “seem” will have to do because to my knowledge, empirical evidence has yet to be compiled — more likely to descend angrily and en masse when he is attacked or even just questioned. Some people describe it as a digital lynch mob.

Sanders’ believers — the word is apt — seem to regard the democratic socialist as He Who May Not Be Questioned. Which is at odds with what a presidential primary is supposed to be. His candidacy — like all candidacies — should expect robust cross-examination.

On age, for example. At the end of a second term, Sanders would be within hailing distance of 90. How old is too old? And can Sanders, an independent, lead the Democrats, a party to which he does not belong? Then there’s his recent tin-eared praise of Fidel Castro, which, putting it mildly, will not be helpful to him or the Democrats with Cuban-American voters in Florida.

And here, let’s say the obvious: No terrorist group or foreign power poses this country a greater threat than its president. Therefore, it is a patriotic necessity to vote for whoever opposes him in November. That includes Sanders. Heck, it includes Mr. T. and Doctor Doom.

Still, it’s hard not to believe that Sanders could shoot someone in the middle of Fifth Avenue and not lose any supporters — and to wonder how we should feel about that. Not that their devotion is hard to understand. You get sick of seeing them that’s got get and them that’s not — meaning you, your neighbors, your kin — lose buying power, college dreams, homes, health. That’s why there’s a Fight for $15 and a new Poor People’s Campaign. It’s why Sanders’ promises — free college, health care, child care — resonate.

But one can understand that and still struggle with a niggling sense that we are sitting through a movie we’ve seen before. It’s not just the delirious supporters rejecting the very idea of skepticism and questions. It’s also the fact of the outsider vanquishing a crowded field, smug pundits assuring us he can’t possibly win the general election, the party establishment terrified he is dragging them to an ideological extreme.

In fairness, history may someday record that he is dragging them exactly where they need to be. But the paradox of this moment is that what we need ultimately may not save us — may even destroy us.

In 2016, America was pulled very hard to the right. Now Sanders proposes to pull just as hard to the left. Consider that symmetry and then ask yourself: What happens when you pull a thing with equal force in opposite directions? Unless it’s very sturdy, it tears apart.

Does this country seem sturdy to you?

— Leonard Pitts is a Pulitzer Prize-winning columnist for The Miami Herald.