Ideological disagreement is one thing — and in fact it’s a good thing. There’s always room for alternative lines of thinking on broad, subjective issues. But clinging to an assertion that is patently, objectively absurd? That’s another thing altogether.

We’re seeing a lot of those these days. More often than not, the absurdities are necessary to justify political actions or objectives. If reality gets in the way, too bad. Whether the adherents admit it to themselves or not, surely they recognize nonsense when they see it.

Examples abound; here are a few:

• Is there anyone who actually believes that a girl can be a boy, or a boy can be a girl? That’s a bizarre idea wholly inconsistent with biology and human history — but it’s now accepted as gospel truth by the Left and promoted enthusiastically. Those who dare disagree are castigated as haters.

Of course, anyone can wish they had been born with a different body, or pretend to change genders, or alter their physical appearance or lifestyle. And we can all agree that no one who thinks or acts on those inclinations should be subjected to discrimination of any sort. Theirs are personal choices and ours is a free country. We treat one another with respect.

But my guess is that even staunch proponents of gender fluidity know that modern miracles such as “male birth” and “chestfeeding” are ridiculous.

• Imagine if Donald Trump’s fevered wish had come true and his vice president had refused to certify the election of Joe Biden on 1/6/21. Does anyone believe that the U.S. Congress and judiciary would have just nodded politely, the nation would have just shrugged its collective shoulders, and Trump would have stayed in office for another four years?

Or does anyone really believe the other variants of January 6 mythology? That Proud Boys with flag poles would have subdued the Capitol Police, beaten back the U.S. Armed Forces, and taken over the United States of America?

Yes, it is true that many Americans believe that there was an insurrection on January 6 — no doubt because the word “insurrection” has been conveniently redefined by media and partisans in two and a half years of relentless propaganda. The American Civil War — four years of brutal conflict taking 620,000 combatants’ lives — was an insurrection; January 6 was not. It was an ugly, stupid riot, carelessly provoked by a man who should not be our next president.

• Does anyone believe that a tiny, fully formed infant child in his mother’s womb is not a human being, has no rights, and deserves no legal protection? Having recently held a squirmy two-day-old infant, kicking her little legs just as she did in her mother’s womb a week before, I don’t believe that for a second.

Who could possibly disagree? Evidently quite a few Americans do, as evidenced by law in at least seven states that allow abortion up until natural childbirth. Under cover of protecting women’s (i.e., voters’) health, those states conveniently ignore the lives of the most vulnerable among us.

• The list goes on. Does anyone really believe that the obviously frail, doddering Joe Biden is physically up to the mental and physical challenges of another presidential term? Or that it’s a good idea to nominate for president someone busy defending himself from indictments (fair or not) on 91 felonies? Does anyone really believe that a flood of unvetted migrants is good for our country? Does anyone really believe that a wholesale switch to electric vehicles will prevent wildfires and hurricanes?

So, is this just an old guy’s grumbling about wildly diverse political views? Do they matter?

I think they do. Party-line positions like these may initially raise an eyebrow or two — but repeated often enough and authoritatively enough, they become part of the landscape, and then sooner or later they become the foundation for policy, behavior, business practices, and social expectations.

Back to the first example above: I suspect that when proponents first floated the notion that gender is simply a matter of personal choice and is completely changeable, most Americans, knowing better, brushed it off — weird, but harmless.

Then, the tsunami, hitting where least expected — our children. Gender anxiety in various forms is now rampant among teens and pre-teens. Having unnecessarily precipitated that problem, we turn to the new cottage industry of specialists who offer “gender-affirming care,” sometimes including drastic surgeries to “transition” their patients from one gender to another.

These are life-altering actions, visited on young people who have not yet grown into the bodies they’ve decided they don’t like. It’s a self-inflicted wound, seeded by our too-casual acceptance of the myth of gender fluidity.

It’s amazing how much trouble hazy thinking — or no thinking at all — will get us into.