You know the character in books or television shows. Or maybe you even have a neighbor, ex-boyfriend or relative like this: The person you can never trust, whom you always have to suspect is up to something — someone who just seems ... scammy.

Well, one such woman is running for president again.

Americans find Hillary Clinton untrustworthy, two-to-one, according to one recent national poll. That's worse than all other presidential candidates, including Donald Trump.

Quinnipiac asked more than 1,000 voters each in Florida, Ohio and Pennsylvania: "Would you say that Hillary Clinton is honest and trustworthy or not?" A full 64 percent of Floridians, 60 percent of Ohioans and 63 percent of Pennsylvanians said "No." Recall that Barack Obama won all three of these states twice.

By comparison, Bernie Sanders, Marco Rubio and Jeb Bush's "untrustworthy" numbers were in the 20s and 30s — basically, they are just hated by hardened partisans.

Donald Trump was the only other candidate who was underwater on the trustworthy question — and Trump's trust deficit was at least 10 points smaller than Clinton's in all three states.

This poll was conducted before Clinton's dissembling performance in an August 18 press conference, in which she literally waved off questions about her erasing public records with an awful joke about wiping clean her personal, long-secret and likely inadequately secured server "with a cloth."

This is the key poll number about Clinton. She actually leads the Democratic field in all polls in all states. She regularly beats serious Republican contenders in polls. But Hillary's "trustworthy" problem is parallel to Mitt Romney's "cares about me," problem. In one poll during the 2012 campaign, only 33 percent of voters said Mitt Romney "cares about people like me." Later, exit polls would show one in five voters voted primarily on that question, and those voters went four-to-one for Obama.

Clinton's trustworthiness problem is not about small white lies. It's that we suspect she is up to something, and that that's why she needs to hide everything. That's why she set up her own email server for all government work, as no cabinet official ever has. That's why she deleted the emails. That's why she has repeatedly obfuscated, and said misleading or false things about the email server. She decided she'd make her email more accessible to hackers in Russia, or ISIS, or China than to a Freedom of Information Act request.

The FBI digging around this question just confirms what most of us suspect: There's something fishy here.

Some political commentators have said it was a dumb mistake for Clinton to set up her own email server and then, after the State Department asked for her work-related emails in accordance with public records laws, delete all emails that she unilaterally decided were not the public's business.

This is the official spin of the Clinton camp: "She didn't really think it through," Clinton aide Jennifer Palmieri told Bloomberg. "And, she has said, had she, she would have done it differently."

But one doesn't accidentally or thoughtlessly build a server outside the reach of official oversight and try to bury requested records. This is all deliberate and premeditated — not thoughtless.

And was her stubborn opacity foolish? Not if she had good reason to hide her emails.

The old saying that the cover-up is more damaging than the crime is impossible to test if the cover-up is so thorough that we don't know what the crime was.

In other words, there would be a lot less heat on Hillary now if we actually knew what she was doing.

Perhaps she's hiding something fairly innocent but politically painful — maybe confident proclamations that everything was going great in Libya following the unauthorized regime change there that she championed.

But she could also be hiding emails showing her promising helpful State Department actions to foreign entities that paid obscene amounts for a Bill Clinton speech. Nobody would be surprised to find something like that — or at least 64 percent of Floridians wouldn't be surprised.

If she wanted us to trust that there were no smoking guns in the deleted emails, she shouldn't have regularly misled about the servers and emails.

First, she declined to inform congressional investigators about her special email server. Then she claimed she set it up in order to avoid using two devices (she used two devices). Then she said — while reading from a script — "there is no classified material" on her server. There was. "I've never had a subpoena," she said. That was false.

In all these statements you see a pattern. She says what she thinks will make her look best, hoping nobody finds out the truth.

Again, we all know people like this. Are Democrats willing to put such a person on their presidential ticket?

Timothy P. Carney, The Washington Examiner's senior political columnist, can be contacted at tcarney@washingtonexaminer.com. His column appears Tuesday and Thursday nights on washingtonexaminer.com.