Rep. Marjorie Taylor Greene often acts as if Congress is a circus — to the point of carrying around a white balloon on Capitol grounds before Tuesday’s State of the Union address.

Her antics during President Joe Biden’s speech are indefensible, and the fact that Democrats have behaved equally badly in the past doesn’t justify her behavior.

But Greene’s shouted accusations that Biden was lying (nine times, by the count of a Politico reporter) offer a chance for sober reflection on when, if ever, we should use that word.

Five years ago, NPR had to defend its policy of not using the word “lie” in its news coverage about former President Donald Trump. Some people were complaining that an NPR correspondent said Trump “falsely inflated” the size of the crowd at his inauguration instead of saying he had lied.

The correspondent pointed out that the Oxford English Dictionary defined a lie as “a false statement made with intent to deceive” and that intentional deception is difficult, and often impossible, to prove.

Previously, an NPR editor wrote that it’s not just the substance, but the tone of journalism that matters, saying “if you present the facts calmly and without a tone of editorializing you substantially increase the chance that people will hear you out and weigh the facts.”

The policy was right. There is judgment implicit in the word “lie,” and news outlets are right to avoid it, along with its even more incendiary cousin “liar.”

But “lie” and its derivatives crept into widespread use after the 2020 election, and it’s no longer unusual to see headlines about the “Big Lie” and “2020 election lies” on not just opinion pieces, but also what is held up as unbiased reporting.

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Calling someone a liar is the stuff of Jerry Springer-type talk shows — or used to be. Now it’s apparently OK to pronounce anything someone gets wrong as a lie, even when it’s obviously a blunder. After the speech, The Federalist enumerated 15 “lies” that Biden told, one of which was that Chuck Schumer, the Senate majority leader, was the minority leader. It was a mistake, for sure, but it wasn’t a lie.

The same article said that Biden lied when he said fast-food workers had to sign noncompete agreements. He was wrong — the practice was limited to restaurants within a few restaurant chains and ended in 2018, according to CNN — but that doesn’t make him a liar, just uninformed on that particular subject.

Democrats have also blithely used the words “lie” and “liar” with no regard for the poisonous effect they have on discourse. Vermont Sen. Bernie Sanders repeatedly called Trump a liar, leading to Rolling Stone magazine denouncing Trump as “liar-in-chief.” And in 2012, the progressive group encouraged people watching the presidential debate between Mitt Romney and Barack Obama to tweet using the hashtag #Mittlies if they heard Romney say something that sounded wrong.

In commentary for the Poynter Institute, PolitiFact founder Bill Adair argued that there’s too much fact-checking done on the statements of national politicians and too little done at the state and local level, where politicians are “largely free to make wild, false claims with little worry about being held accountable.”

Fair enough. But are those wild, false claims lies? Or are the people who say the things just wrong?

Adair seems to believe that many untruths are spread intentionally, saying “political lying doesn’t stop on Election Day, nor at the Capital Beltway. Lies at the local level flourish.”

He goes on: “PolitiFact, which has a modest network of state sites, often finds that politicians in different places repeat the same (false) talking points. Yet with so few journalists monitoring the claims around the nation, most voters don’t know that their representatives are parroting the bogus talking points.”

There are bona fide liars in our midst — many of them under the age of 6. Young children lack impulse control and may lie to test boundaries, sometimes to hilarious effect, like the child who told his parents a monster had drawn on the bathroom wall.

And from troubling accounts about George Santos, it appears that the newly elected congressman from New York may have a lengthy track record of deception. But to its credit, The Washington Post did not call Santos a liar when the publication detailed his “long list of untruths,” instead describing him as a “serial fabulist.”

In his videotaped response to the State of the Union, Utah Sen. Mitt Romney showed how calling out an untruth is properly done, ticking off some of Biden’s eyebrow-raising claims with the amiable tone of someone disagreeing with a good friend: “No, no, no, that’s just not true” — “that’s just plain and simply wrong” — “a bit disingenuous” — and “kind of an exaggeration, let’s put it that way.”

Not only is that sort of response more dignified but it’s also usually more accurate. Trump showed his own hand when he wrote “The Art of the Deal,” saying that exaggeration plays into his brand. “I call it truthful hyperbole,” he wrote. Of course, you could call it a lie — and be like Marjorie Taylor Greene.

Me, I’d rather be like Romney. The State of the Union, entertaining as it was, was “a bit disingenuous” in some places. And as for Santos, serial fabulist sounds about right.