Biden is clearly too old for a second term. Fortunately, Democrats are propping him up.

I’m not a fan of President Joe Biden, but I do not want him to resign the presidency or withdraw from his reelection bid. This is not because he’s good at the job (he isn’t), or because he is honest (not a chance), but because he is the easiest Democrat for Republicans to beat.

Recognizing that Biden has not only lost a step but several flights of mental stairs, progressive leftists are starting to worry. There’s only so much propping up they can do.

Biden’s recent trip to Asia was a testament to why his handlers in the White House do all they can to keep him away from reporters who might ask difficult or serious questions.

The press conference in Vietnam was so bad that it inspired this headline: “Biden Announces ‘I’m Going to Bed’ Before Being Cut Off Mid-Sentence After Several Weird Outbursts at Troubling Vietnam Presser.” And really, that barely scratches the surface.

Go watch any video of Biden from five years ago or longer and compare it to anything you’ve seen during this administration. You will be surprised at the contrast.

Biden was never particularly bright or honest, but what he lacked in intelligence and integrity he made up for with energy and vigor. His infamous confrontation with a New Hampshire voter in 1987, when asked a simple question that caused him to rage about how intelligent and accomplished he had been as a law student, is a prime example of this. It doesn’t matter that everything Biden said in that exchange was a lie — not just wrong, but knowingly false. What matters is that he could handle himself with such vigor in public while lying so brazenly. Biden was clearly of sound mind then. He knew what he was doing, and he thought he could get away with it.

Today, Biden is no more honest than he was then, but he is far less convincing. Now there’s even a question as to whether he’s aware that what he is saying isn’t true. His staff has implored him to stop talking about both his travels on Amtrak and his participation in the Civil Rights movement because it is embarrassing to repeat things that have been debunked this way. Yet he keeps doing it.

The New York Times probably put it too charitably with the headline “Biden, storyteller in chief, spins yarns that often unravel.” That is the most polite way to call out a habitual liar. But now, at age 80, there seems to be more to it.

Apologists have tried to spin Biden’s puzzling performance in Vietnam as simply a side effect of his being tired from travel — “that’s a demanding trip, even for a younger person.” But Biden had been in Asia for days at that point. He was not newly jet-lagged. And in any event, Air Force One affords its chief passenger a relatively comfortable place to sleep.

Even with the excuses, the best his defenders could muster was a bland, “And he did fine.” Except that he didn’t.

Biden is not all there. The public is starting to notice his age, to the point that it has become their top concern about his presidency. Forty-nine percent of respondents to last week’s CNN poll volunteered “his age” as their open-ended response when asked what their biggest worry about Biden’s presidency. That is in addition to other people who cited as their top concern his “mental acuity” (7 percent), his “health” (7 percent) his “ability to handle the job” (7 percent), his “ability to complete a full term (4 percent) and his “stamina” (2 percent). Add it all up, and 76 percent of those surveyed are worried most of all that Biden is not physically or mentally up to a second term as president.

Democrats are becoming the victim of their own organizational structure — a hierarchy more rigid than that of any institution on Earth, including the Catholic Church.

Republicans have to scream and kick each other in public to keep their comrades in line. If they ever shut up, it is because they are terrified that Donald Trump, empowered by his popularity with the party faithful, will smite them with a humiliating public tweet-storm — something he is never afraid to do.

Democrats, in sharp contrast, invariably and silently fall in line and obey party leaders, regardless of what their own voters think about issues or candidates. Only such an organization as theirs — one in which no one dares question authority, openly or behind closed doors — could suppress and hold back so much viable talent in favor of a doddering incumbent whose ability to do the job is so widely doubted, even by rank-and-file Democratic voters.

And again, Republicans do not want Biden to go anywhere. He’s the easiest Democrat to beat, if only for that very reason.

Don’t be surprised if Republicans soon become the ones propping him up — for a time, at least.

Derek Hunter is host of the Derek Hunter Podcast and a former staffer for the late Sen. Conrad Burns (R-Mont.).