If the grand jury in Delaware investigating Hunter Biden’s business ventures does its job properly, it will be pulling on the threads that lead to the president, and already there are signs that is happening.

Regardless of the extraordinary statement last week by White House chief of staff Ron Klain, that the president is confident his son has done nothing wrong, and that the inquiry has nothing to do with Joe Biden or anyone else in the White House, publicly available evidence says otherIt is not just the e-mails and other material on Hunter’s abandoned laptop which point to Joe Biden’s involvement in his family’s multimillion-dollar global influence-peddling schemes when he was vice president.

There is also the six-hour interview Hunter’s former business partner Tony Bobulinski gave to the FBI last year, along with a trove of documents, e-mails and encrypted messages.

Bobulinski has publicly named Joe Biden as the “Big Guy,” referenced in e-mails, whose 10% equity in a joint venture with Chinese energy company CEFC was held for him by Hunter.

Now the identity of the Big Guy has become a topic for the Delaware probe.

At least one of the witnesses before the grand jury has been asked: who is the Big Guy?

Sources familiar with the investigation say Bobulinski is yet to appear, but if he does not testify before the grand jury, something is very wrong.

Perhaps US attorney David Weiss is saving the best for last.

The pressure on Weiss is immense, as the four-year investigation into the president’s son and his business partners, including his uncle James Biden, Joe’s younger brother, threatens to become an election issue in November.

Alarm bells are starting to ring in Democratic circles as the White House stonewalls in the face of increasing media inquiries. In two absurd statements in recent days, White House spokespeople said the president stands by his pre-election statement that Hunter never received any money from China, and he continues to deny that he knew anything about his son’s overseas business dealings.

The White House position is unsustainable.

First, there are the Treasury Department documents presented by Republican Sens. Ron Johnson and Chuck Grassley, along with bank statements on Hunter’s laptop showing millions of dollars paid by Chinese company CEFC to Hunter and his business ­partners.

Then there is evidence, from Bobulinski and from the laptop, that Joe met Hunter’s foreign business partners on multiple occasions while he was vice ­president.

In addition, there is evidence on the laptop that Hunter and his father had co-mingled finances and shared bank accounts, and also that Hunter paid some of Joe’s household bills, including a monthly phone bill and maintenance and renovations on one of his Delaware properties.

China connections

What is not properly understood, especially by the catch-up merchants and Biden apologists of the left-wing media, is that the millions of dollars wired by CEFC to Hunter and Jim Biden and partners was payment for work done in the last two years of Joe’s vice presidency, using the Biden name to advance the interests of Communist China in Oman, Luxembourg, Romania, the Middle East and Asia.

This included $6 million paid in two wires in February and March 2017 to Rob Walker, a trusted Biden family friend, and former Clinton administration official whose wife, Betsy Massey Walker, had been Jill Biden’s assistant when she was second lady.

CEFC was the capitalist arm of China’s Belt and Road initiative, President Xi Jinping’s imperialist program to compromise smaller countries, bribe their officials, buy up their energy resources and infrastructure and ensnare them in debt traps, in a bid to take over the United States as the world’s economic superpower.

‘Blowout’ ahead?

The Biden partnership was crucial to open doors and give CEFC a veneer of respectability.

Walker would be a useful witness for the Delaware grand jury, as would another of Hunter’s business partners Eric Schwerin, president of his firm Rosemont Seneca, and general factotum.

We know that Delaware investigators issued a subpoena in 2019 to JPMorgan Chase bank for international financial transactions involving Hunter and James Biden, Schwerin and another former business partner, Devon Archer.

Schwerin has extensive knowledge of Biden family finances and appeared to have signature privileges over Joe Biden’s money, as shown by e-mails on the laptop.

“Your Dad’s Delaware tax refund check came today,” he e-mailed Hunter on June 10, 2010. “I am depositing it in his account and writing a check in that amount back to you since he owes it to you. Don’t think I need to run it by him, but if you want to go ahead. If not, I will deposit tomorrow.”

As public awareness of this scandal grows, Democratic political consultant Doug Schoen, in a careful article in The Hill over the weekend, expressed his party’s concerns.

If Joe Biden is found to have profited from Hunter’s business deals or used his position as vice president to benefit his family, Schoen wrote, “what is now likely a red wave election could turn into a massive blowout that is more substantial than anything seen in recent history.”

He’s not kidding.

Government turns blind eye to immigrant night flights

Another suspected migrant charter plane flew into Westchester County Airport on Saturday night, indicating an acceleration in tempo over recent weeks. This time, Rob Astorino, former Westchester County executive, aspiring Republican governor, and dogged critic of the Biden administration’s secret operation to fly illegal migrants from the southern border to New York, watched the iAero plane land at 9:43 p.m.

The Boeing 737 remained hidden from view on the tarmac next to Ross Aviation East for more than an hour while unloading its passengers into three charter buses.

When the buses emerged from the airport, just after 11 p.m., two headed south on I-684. Astorino followed the third, which he estimated contained 25 to 30 teens. That vehicle drove north 20 miles to Somers, and vanished into the grounds of a school at around midnight.

“The Biden administration must have such contempt for Americans to blatantly wave illegal immigrants across the border, fly them into our communities and then tell us we have no right to ask questions,” said Astorino. “Gov. Hochul must agree, since she hands out our tax money by the billions for them to come here.”

Thankfully, this time, the charter bus traveled at a sedate pace. Last week, with The Post in hot pursuit, one J&F coach reached speeds approaching 80 mph in the pouring rain.

When I called the company to ask why the hurry, the person who answered hung up the phone. Other buses we followed last fall also hit breakneck speeds, suggesting the safety of their human cargo is not a top priority for the Biden administration.

But secrecy sure is.

Heading to Broadway in September is the latest incarnation of 1776, the musical about the signing of the Declaration of Independence, with a new cast described by Deadline Hollywood as entirely “female, non-binary and trans”.

No doubt a few penises will be floating about on stage but not one – ahem – man, in the original sense of the word.

Who knows how this epicene ensemble will deal with George Washington’s desire for a “manly, virtuous and happy people”, or James Madison’s ode to the “great, manly, and warlike virtues”.

Next they’ll be calling the Founding Fathers the “Founding Co-Parents”.

It’s a fitting portent that on his 100th day in office, Eric Adams was struck with COVID. Sunday marked 100 days of our new mayor not getting much done, despite a blizzard of fine words. With major crime up 44 percent this year, and a summer of violence looming, he’s going to have to do more than talk. Maybe he can use his COVID isolation this week to come up with fresh ideas. Better yet, give Rudy Giuliani a call.