It’s easy to forget because he’s usually invisible but we still have Joe Biden as president for four months.

That’s a scary prospect considering his obvious cognitive decline. He’s spent almost half his presidency goofing off and being shielded from scrutiny but the situation is rapidly getting worse.

The fate of the free world should not be left in the hands of a man who can’t remember where he is or what he’s meant to be doing at any given moment.

On Saturday, for instance, he made the prime ministers of India, Japan and Australia shlep to Wilmington, Del., for the annual meeting of the Quad, a partnership designed to keep an increasingly aggressive China in check.

In public remarks livestreamed by the White House the president forgot that he was supposed to introduce Indian Prime Minister Narendra Modi.

“Who am I introducing next?” Biden asked the crowd.

After an awkward silence, he started shouting “Who’s next?” before Modi raced on stage all smiles and saved the day.

The whole thing was an embarrassment. Starting with the fact that the Quad leaders were not being hosted with dignity at the White House and instead were housed at the rundown Hotel DuPont in Biden’s podunk hometown and had to hold their summit at Archmere Academy, the posh Catholic prep school Biden attended while his younger brothers had to content themselves with the local public school.

At least the Quad leaders got individual tours of Joe’s palatial estate, which has been off limits to the media due to fascinating speculation about how the self-described “poorest man in Congress” could afford such luxury, a Georgian pile Joe had built by master craftsmen from Bryn Mawr on a lake in the ritziest neighborhood in Delaware, an upgrade from his former Du Pont mansion.

In photographs dribbled out by the Australian delegation, we got a glimpse of the grandeur of the custom-built wood paneled library where Joe secreted classified documents dating back to his Senate days, for which he never was held accountable because special counsel Robert Hur thought he was too old and forgetful for a jury to convict.

But why was this important meeting being held in Wilmington at all? The White House patched up a story about Biden wanting to show off his hometown but he’s never had the urge before and, quite honestly, there’s not much to show off.

More likely it was that the White House was already booked out for the self-aggrandizement of the relentlessly ambitious first lady.

…

Whether it’s Jill or someone else running the country, the bottom line is that we don’t have a functional president.

This is a constitutional crisis.

Kamala Harris is most to blame because she has the constitutional duty as vice president to ensure the president’s brain is not AWOL.

She also knows more about Biden’s cognitive health than anyone, apart from Jill and Hunter Biden.