Is it possible we’re witnessing the beginning of the end of Donald J. Trump’s presidency?

The signs and portents are coming so fast that it’s hard to keep score. Over the weekend, Trump threatened to file a lawsuit against the NBC network because “Saturday Night Live” made fun of him again — as they’ve lampooned every president since Jimmy Carter.

Is the big crybaby cracking? It sure looks that way.

OPINION

Last week, Trump tried to run a nationally televised bluff past Nancy Pelosi over funding for his vaunted Mexican wall. He vowed to shut down the U.S. government at Christmas if he didn’t get his way. Pelosi called him and raised him. Go ahead and call a vote if you think it’s a winner, she said. Because, see, Pelosi does her homework. Trump’s not the first blowhard she’s encountered during her long political career. Having counted the votes, the incoming speaker knew the president’s threat was empty bluster.

Congressional Republicans soon began fighting among themselves. So the president folded, characteristically sending Sarah Huckabee Sanders out to announce that “at the end of the day, we don’t want to shut down the government.” Otherwise, see, Trump would have had to admit being outwitted by a woman older than his first wife. Unthinkable.

Elsewhere, Wired magazine recently compiled a list of ongoing criminal investigations involving the president, his immediate family, the Trump Organization, etc. There are 17 altogether, involving several jurisdictions. They include, of course, the most dangerous and consequential of all: special counsel Robert Mueller’s probe of the 2016 Trump campaign’s clandestine dealings with the Russian government. And the deeper Mueller digs, the more Trump looks like a wholly owned subsidiary of the Kremlin.

But hold that thought. Even Trump’s 2017 inaugural committee is being probed. It raised a reported $105 million for the ceremony — much of it from “straw” donors whose real identities are unknown. (Foreign contributions are illegal.) Some $40 million remains unaccounted for. I know whose pockets I’d search.

Seventeen investigations! Think of the legal bills. Even granting that the man rarely, if ever, pays his lawyers, you’ve got to wonder if the time’s not coming for Trump to cut his losses, cop an immunity plea and walk away.

Just this week, the president reportedly came to an agreement with the attorney general of New York to shut down the Trump family foundation, which appears never to have been anything but a slush fund and a vehicle for tax fraud. Even what few legitimate charitable donations it made to veterans organizations were presented at staged political events — a violation of laws governing tax-exempt charities.

Some details are downright comical. Among other absurdities, the Trump charity bought a large oil painting of the great man himself to adorn his golf clubhouse. According to The Washington Post, the foundation’s largest expenditure was a $264,231 gift to the Central Park Conservancy in 1989 to restore a fountain outside Trump’s Plaza Hotel — the luxury hostelry he drove into bankruptcy in 1992. A $7 gift to the Boy Scouts of America appears to represent Donald Jr.’s enrollment fees.

How does that grab you? A billionaire claiming a phony tax deduction for his kid’s Boy Scout dues.

But what’s got to have Trump running scared is Mueller’s Russia probe. It’s not just that Trump’s campaign director, Paul Manafort, his national security adviser, Gen. Michael Flynn, and his personal lawyer, Michael Cohen, have pleaded guilty to felony crimes. It’s that the public is gradually catching on. Fully 62 percent of Americans in a recent NBC-Wall Street Journal poll say they believe that Trump’s been lying about his dealings with Vladimir Putin.

And you know that’s one number that’s never going down.

To anybody who’s read the fine print in Mueller’s legal pleadings, it’s clear things can only get exponentially worse for Trump. Here’s how Mueller explains the effect of Michael Cohen’s false testimony to Congress about the president’s secretive Trump Tower Moscow project — the one he lied about repeatedly during the 2016 campaign.

“If the project was completed, the Company could have received hundreds of millions of dollars from Russian sources in licensing fees and other revenues. The fact that Cohen continued to work on the project and discuss it with Individual 1 well into the campaign was material to the … investigations, particularly because it occurred at a time of sustained efforts by the Russian government to interfere with the U.S. presidential election. Similarly, it was material that Cohen, during the campaign, had a substantive telephone call about the project with an assistant to the press secretary for the President of Russia.”

“Nothing to do with Russia,” Trump said, a barefaced lie. So would a man who’d claim a phony seven-buck tax deduction sell out his country for hundreds of millions?

He’d do it for a lot less than that.

And deep down, almost everybody knows it.

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