All those who believe the Democratic presidential selection is already decided, raise your hand.

Uh, not so fast, Hillary. Granted, that’s an old joke and granted she’s still the “presumptive nominee,” she’s had her invincibility challenged by a man, Sen. Bernie Sanders, who embraces the socialist

label.

Part of that may be the disgust of so many in the party with the nation’s severe economic unfairness, which is right in the Sanders wheelhouse. But a lot of the Hillary slippage seems to be caused by the impression that she’s a lousy candidate. At least, many have drawn that conclusion.

They have been turned off by her seeming total lack of spontaneity, her tightly scripted campaigning and the efforts by her staff to stifle any ad-libbing whatsoever in her appearances, along with their control-freakish battle with the press. Most damaging, though, are the widely held questions about her integrity.

The continuing controversies ver her use of a private email server when she was secretary of state have raised “what is she trying to hide” concerns, the same ones that have swirled around the Clintons throughout their political lives.

Add to that real or manufactured suspicions about their massive family foundation and rapid accumulation of wealth, and she is stuck with a perception that she plays fast and loose with the truth.

Of course, Republicans are only too happy to pounce all over this angst.

They were anything but shy about it during their first debate extravaganza in Cleveland. “Hillary Clinton lies about Benghazi,” declared Carly Fiorina, “She lies about emails.”

Obviously, Fiorina is on safe ground, teeing off on the one who’s still the GOP’s likeliest opponent. But in Hillary’s own party, a big number of leaders are queasy about her vulnerabilities.

Calling Joe Biden!

The vice president has been devastated by the death of his son Beau. But even as he goes through the agony of his loss, a column by Maureen Dowd has appeared in The New York Times, citing sources who described the young Biden’s conversation with his father as Beau was deteriorating.

According to Dowd, he strongly expressed his wish that his father run for president.

No one is disputing the story, neither the Bidens nor anyone else who might be in a position to.

The point is that the column appeared at all; longtime associates of Joe Biden would not be fanning out to spread the word if they believed it would offend him as he and his family struggle with their raw emotions.

And the issue wouldn’t even come up if Hillary Clinton had been building her lead, instead of frittering it away.

If Biden did get in the race, he’d have a lot of ground to make up, but suddenly his party would have its own drama. So far, it’s the Republicans who have tried to outdo each other in the bizarro department. Even those who are professional extremists have been beaten in the outlandish game by “The Donald.” Look at how he turned the first Republican debate into a rowdy brawl.

The candidates-other-than-Trump are not pleased, but they all have one basic agreement.

As Mike Huckabee put it in his closer: “It seems like this election has been a whole lot on a person who has been very high in the polls, who doesn’t have a clue about how to govern, a person who has been filled with scandals and could not lead, and of course, I’m talking about Hillary Clinton.”

The bigwigs on the Democratic side are clearly concerned.

They privately worry that Hillary Clinton has stumbled out of the gate. So that explains the scramble to make sure that when they raise their hands at the party convention, they have a strong leader to choose.

Bob Franken is a longtime broadcast journalist including 20 years at CNN