This is actually giant sloth dung, but potato, potato. (Chip Clark/SMITHSONIAN INSTITUTION)

This just goes to show that the secret of originality is remembering everything you hear but forgetting where you heard it. (I forget where I heard that.)

Gary Johnson might be one of those footnotes who sail into the history books on the wings of a single quip. Does it matter who said it first? It’s a question like the one they pose in glossy magazines: who wore it best?

Coming from Rush Limbaugh, expert provocateur, it hardly made a sound. From the nervous, awkward Gary Johnson — you know you’re a debate supernumerary when you stand farther from the center of the podium than Rick Santorum — it caught fire.

The class clown can joke all day long. Eventually we cease listening. But let that quiet kid in the back suddenly burst out with a poop joke, and the crowd goes wild. It’s all, as they say, in the delivery.

Lame? Sure. But the dogs had their day. “Ah, scatological humor!” we said. “Someone’s finally raising the level of discussion!”

They say the way to a man’s heart is through his stomach. Well, the way to the electorate’s heart is through the large intestine. Thursday night’s debate, for the most part, was about what divides us, not what unites us. Johnson changed that trend. If there is one thing that unites us as a nation, it is that we don’t have jobs and enjoy jokes about pooping dogs.

It is in moments of crisis that this sort of humor is most needed. History supplies numerous examples. Abraham Lincoln’s original Gettysburg Address included a line about testing “whether this nation, or any nation, so conceived and so dedicated, can long ordure,” but his editor made him remove it. “The only thing we have to fear is fear itself,” said Franklin Roosevelt. “Also, “ he added, under his breath, “doodies.” Woodrow Wilson’s Fourteen Points only failed because they didn’t stop at Number Two.

“But it’s not original!” Does it matter?

Of course, they say that when a nation has to resort to the bathroom for its humor, the writing is on the wall.

I forget where I heard that one.