How appropriate that the Biden presidency is ending with an act of self-dealing that he and his allies insisted, with great righteousness, would never happen.

Joe Biden was always a scam, and his pardon of his son, Hunter Biden, is just the latest evidence.

No one should have believed Biden’s flagrant lie that he wouldn’t pardon Hunter for his tax and gun crimes and other potential wrongdoing.

The president has a long record of dishonesty, about his own biography (which blew up his first presidential campaign in 1988) and especially about the family influence-peddling business that was at the root of Hunter’s tax evasion.

Every politician ends up shading the truth somewhere along the line, and it was going to be awkward for President Biden to admit that he might pardon his son. When asked about the possibility, though, the president could have said “no comment.”

Instead, he flatly denied it, and his allies wove his denial into a narrative about Biden’s abiding commitment to our system of justice. He was “a president living the rule of law” (MSNBC legal analyst Andrew Weissmann), and “a true American who believes in democracy and the way the system is supposed to work” (Joy Behar of “The View”). Etc., etc.

Now, Biden has made all the people who issued these stirring testimonials look like naifs and hacks.

Their mistake was attributing any grandeur to Joe Biden. He’s made a long, undistinguished career of being a middling politician from a small Democratic state and had just enough staying power to become president when he was already a has-been.

Biden was puffed up by Democrats’ media supporters into a world-historical figure who had saved American democracy by winning one election against Donald Trump, who, of course, simply came right back to win another against his chosen successor, Kamala Harris.

He had the health and mental acuity to serve another four years in office — never mind his marked decline that was plain for all to see.

And he was, whatever else you thought of him, rigorously ethical. This was an incredible claim given the amount of money that came sluicing into the family coffers thanks to the generosity of dubious foreign actors.

Biden denied knowing anything about Hunter’s business dealings — a blatant lie.

He denied meeting with any of his clients — yet another lie.

And, true to form and appropriately enough, he lied about the prospect of pardoning him.

In justifying his act, Biden issued a misleading statement about the case and implied that his own Justice department, the institution whose integrity he was supposed to be upholding, engaged in a politically motivated prosecution of his own son. He concluded with perhaps the most galling falsehood of all — “For my entire career I have followed a simple principle: Just tell the American people the truth.”

Maybe, sunk in self-deception, the president somehow believes that, but no one else should. He’s ending his term with a self-interested act that will only serve to convince more people that self-professed defenders of our institutions like him can’t be trusted.

Rich Lowry is editor in chief of National Review