Gosh, this is painful to watch. Somebody, stop Joe Biden before he talks again.

Better yet, have the putative favorite to win the 2020 presidential election (based on polls saying he’s the Democratic leader and would also defeat Donald Trump) practice in front of a mirror. The speeches would be canned and boring, but that would be better than watching Biden require a podiatrist or an oral surgeon to wedge his foot out of his mouth.

George W. Bush used to hear the jokes about his speaking mistakes. To his credit, Bush had a sense of humor about it, which is lacking in Biden and almost tragically absent in Trump. Next to these guys, GWB was Shakespeare.

Biden’s mouth has gone through Iowa like Sherman’s army marched through the South, leaving damage wherever it goes. Already facing muffled questions about his age, Biden sounds like an Old Gaffe-er, misspeaking in ways that have punctuated his long career but were never spotlighted as they are now.

Here is what Biden has said in Iowa:

“Poor kids are just as bright and talented as white kids.”

“There are at least three (genders).”

“We choose truth over facts.”

Predictably, his reservoir of supporters defend his integrity, if not his vocabulary. The first mistake is politically incorrect but delicate, for it inadvertently gives credence to what civil rights activists insist is as true as it is unjust - that a disproportionate number of poor kids are of color.

On the second point, Biden’s crash course in biology and sociology led to a follow-up question from a young woman who asked him to identify what three (or more) genders there were.

"Don’t play games with me, kid,'' Biden snapped, showing a temper that does not suit a consensus builder well. Later, he grabbed her arm to explain his support for same-sex marriage, ignoring the no-touching rule that has put politicians (especially males) on notice these days.

His defenders point out that the woman was part of a “right-wing” college group. I don’t consider myself a right-winger, but I will say this: I don’t think the question was unfair.

It exposed Biden as someone who hasn’t exactly given deep intellectual thought to the complexity of gender identity - and that’s what it deserves, especially from lawmakers. It was a hasty, shallow throwaway line that smelled of saying “everybody, please like me.”

“At least three” indicates a specific, identifiable number. Well, sort of.

And, “truth over facts.” The Trump people can use this video in every 2020 GOP ad. But people make mistakes, we all do, and this George W. Bush-like goof would be hilarious and inconsequential - if it didn’t add to a rapidly growing list of gaffes and blunders.

I am not endorsing Biden, but I do believe in the foundation of his campaign - consensus, not reckless radicalism. It says we have to work toward one another to settle differences, not turn our backs and flee in anger to our separate corners.

The message is solid and sound. Much less clear is whether he’s the one to deliver it.

Biden’s support base has been resilient, and its response is consistent: Come on, we know what he means. It’s the thoughts which count. Besides, nobody could be worse with words than Trump, whose impulsive tweets and remarks show not only misjudgment or malapropism, but malice and hate.

My problem with that defense is that I refuse to let Trump’s stupid tweets become the bar by which other, arguably less stupid remarks are judged and excused. Millions on either side think it’s OK for even world leaders (or world leaders-to-be) to regularly blurt out anything these days. I am not one of those people.

We should not expect perfection in the fishbowl of presidential politics, but words do matter - perhaps now more than ever, after we’ve experienced a president who uses words like a carving knife. Isn’t there anybody out there who can give us leadership in words, thoughts and action, rather than forcing us to settle for one, two or none?

Biden’s constant blunders expose either poor preparation, or an obstinate refusal to admit a flaw (at least to himself) that could be mitigated, if not corrected.

Frankly, when he talks this way (or by grabbing the student, acts this way), he comes off as just what his critics say he is: an old man, set in his ways and without the active mind to connect his traditional brand of government to a 21st Century society.

So no, I don’t excuse all of these mistakes and blunders. And this is not coming from someone delighted to see him fail, but from someone who wants consensus government to win the day over Radical Left versus Radical Right - if not led by Biden, then by someone, even though very few someones seem willing to try.

The Democratic nomination remains Biden’s to lose. If he does, the mirror he should be using to practice his lines will show him who was to blame.