Why can’t Hillary Clinton pull away from one of the worst presidential candidates in recorded history? The failure rests squarely on Clinton and the tight circle of people around her who feed her natural suspicion of anyone outside that tight-knit group.

I’m well aware of the contributing factors that led to The Big Stumble, a.k.a. the Clinton campaign hiding an illness until a video of the Democratic candidate’s near-collapse Sunday emerged.

Over the years, conservatives have blown up smallish issues into supposed scandals. Media outlets have fanned the flames of those stories ever bigger. As The Washington Post’s Karen Tumulty wrote in a recent article, “An entire industry has grown up around Clinton scandals, pseudoscandals and conspiracy theories.”

That same article also makes a strong case for how the Clintons themselves spread the seeds that sprouted into the “vast right-wing conspiracy.”

And in this campaign, the ongoing attempts by Clinton loyalists to blame everyone but themselves and their candidate is a dangerous delusion that may culminate in Donald Trump winning the White House.

Clinton’s instinct to only come clean when her hand is forced — whether this gut reaction emanates from an intense level of privacy or an aversion to transparency — is a big reason people are lukewarm — or worse — about her. And why people don’t trust her.

Spare me the “but Donald Trump is so much worse” argument. Of course he is. Case in point: If Trump had made the “deplorables” comment that Clinton made Friday night, it would have been another “there he goes again.”

I am in no way saying there’s any equivalence between Clinton’s behavior and Trump’s. But neither am I willing to let Clinton and her advisers off the hook for decisions that weaken her oft-stated desire to be more transparent and instead build the case that she wants to obfuscate.

Democrats who aren’t feeling nerves right about now should check themselves for a heartbeat. Her team’s tendency to too often go dark at the worst possible moments is no way to build enthusiasm. Not to mention that it gives Trump even more ammunition — and he has no scruples about how he’ll drop those bombs.

Count me with former President Obama adviser David Axelrod, who tweeted yesterday: “Antibiotics can take care of pneumonia. What’s the cure for an unhealthy penchant for privacy that repeatedly creates unnecessary problems?”

Jill Abramson, in a column for The Guardian, went even further after the big pneumonia reveal. She suggested that Clinton’s best way forward is radical transparency. Abramson understands that just because she trusts Clinton, “it’s clear that most voters, including some loyal Democrats, don’t.”

Abramson would have Clinton release the transcripts of her Wall Street speeches and a list of all she was paid to give. Ditto for records and correspondence clarifying her role at the Clinton Foundation.

It’s plausible to see how Clinton got to the Big Stumble moment Sunday morning, which happened during the Sept. 11 commemoration in New York. She’s not the first hard-charging woman or man I’ve observed let a cold turn into a bad cold turn into bronchitis turn into walking pneumonia.

Yet despite apparently finally getting to a doctor Friday and learning of the walking pneumonia diagnosis, she didn’t want to miss the 9/11 event for both political and personal reasons. She didn’t want to feed the already rampant health rumors. She didn’t want to be portrayed as “weak.”

A far more sensible course would have been to announce Friday that she had the illness but would attend the event before taking a few days off the campaign trail. Given all the nonsense out there about health problems she doesn’t have, how could no one in her inner circle see that she was playing with fire?

In the end, the path Clinton chose — feeling boxed in by the Trump people about the health rumors — led her to box herself in. And unfortunately it gives fodder to the ongoing criticism that causes many of her supporters to get itchy: She’s simply not forthcoming.

The tendency to conceal until forced to do otherwise is the root of why it’s been difficult for me and many of my liberal female friends to work up huge enthusiasm about this campaign. And that goes double for the bigger stuff. The email server story and the pay-for-play Clinton Foundation issue weren’t exactly shining moments.

Let me be clear: I’m talking about what I see and hear from Clinton, not any “vast right wing conspiracy” or duped media stooges.

I’ll almost certainly vote for Clinton — she’s eminently qualified and the alternative is manifest danger. Yet I have some concern that her victory will validate in her mind — and in that of her advisers — that evasive behavior wins the day.

She will be able to say: See, tell them nothing.

That is simply not a good thing for our country. And not what I’m looking for in a president.

Sharon Grigsby is a member of the editorial board of the Dallas Morning News. Readers may email her at sgrigsby@dallasnews.com