If she wants to become the first female U.S. president and save the world from President Donald Trump, Hillary Clinton is going to have to do something that goes against her nature: She has to come clean — about her health, about her wealth, about her speeches to Goldman Sachs, about her cozy ties to elite plutocrats, about her emails, about everything.

Clinton took ill last weekend and had to leave a ceremony in honor of 9/11 victims, who are still dying at a dreadful rate from their exposure to toxic air and toxic lies from officials in Washington and New York. Her campaign says she has a mild case of pneumonia, which is certainty not a shock considering her age and the grueling campaign schedule she’s been on for more than a year. With modern medicine, her pneumonia is probably no big deal.

Except, of course, everything is a big deal with Hillary Clinton. Instead of announcing immediately that she’d been diagnosed with pneumonia and was resting after a minor setback, Clinton kept everyone guessing for hours. What was wrong? Where was she? Was she on her death bed?

“ With Hillary Clinton, it’s hard to find the crime, but it’s easy to see the cover-ups. ”

The intrigue was heightened because Trump’s campaign and his cronies in the right-wing media had been spreading rumors for weeks that Clinton is too sick to be commander in chief.

What should have been a sidebar became the big headline on a day when the focus could have been the stark contrast between the two candidates on how each of them had reacted to the deadly attacks 15 years ago in Manhattan, Arlington, Va., and rural Pennsylvania.

It could have been a story about how Clinton the senator acted like a statesman, rushing to the scene and standing with the victims, the first responders and the clean-up crews for years and fought for them against a government that didn’t care about them except as pawns in a geopolitical game. And about how, right after the World Trade Center came crashing down, Trump the con man bragged about how a building he owned was then the tallest in the financial district.

It could have been a story about how one candidate was empathic and effective, and how the other was selfish and cynical. But instead it was a story about how Clinton can’t tell the truth.

Let’s be clear here. Donald Trump is without a doubt the most dishonest and corrupt man to ever to be nominated by a major political party. His lies are legion. He brags about his corruption.

But it’s Hillary Clinton who is perceived as deceitful, a perception based on her instinct — honed over more than two decades of investigations, attacks and innuendo — to dissemble, to tell half the story and only under duress, to make excuses, to whine about how everyone is unfair to her.

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Clinton has a point. Has there ever been a major public figure who’s been investigated so thoroughly with so little to show for it? Everyone says Hillary is a crook, but no one can tell you what the crime was. There sure has been a lot of smoke, but no one’s found the gun.

But as Richard Nixon so accurately predicted on his secret tapes: “It’s not the crime that gets you; it’s the cover-up.”

With Clinton, it’s hard to find the crime, but it’s easy to see the cover-ups. It seems the only thing she learned while assisting with the investigation of Watergate was that Nixon was right: When you are cornered, deny everything, hide from your inquisitors, deploy weasel words to answer legitimate questions.

Remember, hiding from her persecutors was the motivation behind her use of a private email server while she was secretary of state. As she told one confidante: “I don’t want any risk of the personal being accessible.” But in a world of WikiLeaks and email hackers, the personal will always be accessible.

The only safe course is to never write, speak or do anything that you’d be ashamed of if it appeared on the front page of the Washington Post.

After a quarter-century in the public eye, Hillary Clinton still clings to the foolish idea that she can have some privacy. She can’t — at least she can’t while running for president. Everything will come out, and she might as well get ahead of the story by coming clean.

It must really gall her that questions about her integrity could derail her dreams right at the finish line, considering that her opponent is a man utterly devoid of any character. Hillary Clinton certainly has her flaws, but she’s no Donald Trump.

It’s time she proved that to the voters.