So guess what? In the last weeks before the election, the Hillary Clinton campaign did no polling. No. Polling. Whatsoever. Oh, it had data. Lots and lots of data. Analytics, even. Data analytics! But it had no independent information on the overall field of battle in states like Florida, Michigan, Virginia, North Carolina and Pennsylvania.

So when the election began to turn Donald Trump’s way, the Clinton campaign had no idea.

This is one of the thousand revelations in “Shattered: Inside Hillary Clinton’s Doomed Campaign,” the new book by Jonathan Allen and Amie Parnes that, for political junkies, redefines the word “juicy” for our time.

Campaign honcho Robby Mook “was worried about overspending . . . so he declined to use pollsters to track voter preferences in the final three weeks of the campaign.” Mook had learned from his time on the Obama 2012 campaign, Allen and Parnes write, that “old-school polling should be used for testing messages and gauging the sentiments of the electorate and that analytics were just as good for tracking which candidate was ahead and by how much in each state.”

Guess not.

Allen and Parnes report that the Republican National Committee did know — but just couldn’t accept it. The RNC didn’t brief reporters on early November polling data it had developed in Michigan and Pennsylvania “because the upticks there were so rosy that party officials didn’t believe their own data.”

The day after the election, Hillary asked Mook “which decisions had been misguided, where they had erred in strategy and tactics. ‘Our data was wrong,’ he said . . . ‘OK,’ she replied.”

It is true that, but for 100,000 votes in three states, Hillary Clinton would be president today. It is also true that she ended the election with 3 million more votes than Trump. But it is also true, as “Shattered” makes indisputably clear, that she was unquestionably the worst major presidential candidate in our lifetime.

Others (like Bob Dole) did far worse. But they likely never really had a shot. Hillary had no business losing an election to Donald Trump — but Allen and Parnes pile up headshaking detail after headshaking detail from the very beginning of her campaign to its end showing that she and her people were incapable of making a good call.

About anything.

Hillary’s dead-end defenders and those who want a Satan-ex-machina explanation for the November result can point to FBI Director James Comey’s stop-and-start-and-stop email investigation or Russian meddling. But “Shattered” should shatter any illusions that the Hillary election machine would have run smoothly or successfully in their absence. The campaign was a disaster from the get-go.

The question is: Why?

The answer, if I may be narcissistic for a moment, comes straight out of “Hell of a Ride,” the book I wrote in 1993 about the disastrous George H.W. Bush re-election campaign the year before.

I describe a scene in which campaign chairman Bob Teeter called Bush’s speechwriters into a meeting in June 1992.

Teeter set before them a chart that looked like the layout of “Hollywood Squares” or the “Brady Bunch” title sequence. Each of the nine boxes had a message the speechwriters were to use in crafting their work — things like “I have been president for 3½ years: Major accomplishments/record.”

The box in the center — Paul Lynde, if you will — read: “Theme/Slogan/Name.”

There was nothing else in the box. “What I want from you,” Teeter said, “is to help me fill this empty box.”

After nearly four years as president, eight years as vice president and nearly 20 years in public life before that, Bush and his closest advisers could come up with no simple reason to give the voters for presenting him with a second term.

So, too, Hillary Clinton. Whatever Trump’s manifold weaknesses, that is what he had in abundance — Make America Great Again.

And Hillary? It was the empty box all over again.