President Donald Trump is a liar.

This is not a difficult conclusion to draw. You don’t need to be a bitter partisan to come to this conclusion. It’s perhaps the single most banal conclusion to draw from Trump’s behavior over his political life.

That political life began when he lied about President Barack Obama’s birth certificate. He refused to back down from that lie for years, until he eventually lied about his birtherism.

Trump lies habitually -- not strategically, as many politicians do, but constantly, on matters great and small. His lies appear to be contagious, with his aides forced to pick up his bullshit and carry it onward.

“There has never been a serial exaggerator in recent American politics like the president-elect,” wrote Washington Post fact-checker Glenn Kessler in December. “He not only consistently makes false claims but also repeats them, even though they have been proven wrong. He always insists he is right, no matter how little evidence he has for his claim or how easily his statement is debunked.”

Trump’s actions take a blowtorch to general standards of political discourse.

And so it was surprising but perhaps not shocking to discover that a writer at The Washington Post’s The Fix blog declared Sen. Bernie Sanders’ (I-VT) tweets criticizing Trump for “shamelessly” lying were a tragic violation of our political norms.

At The Savvy House That Chris Cillizza Built, Amber Phillips presents Sanders’ comments as equivalent to Trump’s evidence-free, much-denied claim that Obama illegally ordered his phones tapped (Four Pinocchios, according to the Post’s Fact Checker blog):

One side of the aisle is accusing the president straight-up of lying. In 2017, that's just another day in politics.

This is the state of our political discourse right now. Political norms — like, don't accuse the president of the United States of lying without evidence, or don't accuse the former president of the United States of wiretapping your phones without evidence — have been eviscerated.

Trump says Obama tapped his phones without evidence, Sanders says he’s lying, and Phillips concludes that Both Sides are at fault. Trump's tendency to lie is so brazen that he's actually managed to get Sanders and Sen. Ted Cruz (R-TX) to agree on the subject. But for Phillips, calling Trump a liar is not an accurate diagnosis of reality, but a partisan Democratic tactic. In 2017, that's just another day in political analysis.

“Plenty of nonpartisan observers would agree that the extraordinary claims Trump is making have no precedent in modern-day politics,” Phillips writes. “Here's the problem with using the ‘L’ word in politics, though. To say someone's lying suggests that you know they don't believe what they're saying.”

Phillips is channeling the talking points of the Trump administration. Sean Spicer used his first appearance before the press corps as White House press secretary to, in the words of Post columnist Margaret Sullivan, “brazenly lie” to them. Asked at a subsequent briefing if he would “pledge never to knowingly say something that is nonfactual,” Spicer responded that his “intention is never to lie,” but at times he will unknowingly pass along incomplete or inaccurate information, and that it would thus be unfair to “turn around and say, ‘OK, you were intentionally lying.’”

Kellyanne Conway, for her part, has termed critics calling Trump a liar “dangerous to the democracy,” not too far from Phillips’ declaration that comments like Sanders’ are destroying political discourse and making it harder for Trump to pass legislation.

“All of that is why we in the media are careful not to call Trump a ‘liar,’” Phillips concludes. “But top Democrats like Sanders feel no such hesitation.”

The press has at times been hesitant to call Trump a liar, but the hard and fast rule Phillips wants to cite does not exist. At the Post, her colleagues Sullivan, Greg Sargent, Erik Wemple, and Jennifer Rubin have all highlighted Trump’s “lies.” Rubin is a conservative, suggesting that one need not be a partisan to use such terminology; writers at National Review and The Weekly Standard have done the same.

If what Phillips means is that major news outlets have not referenced him as such in their news coverage, she is closer to the mark -- but still wrong. Several outlets, including the Post, have followed the line of reasoning Phillips uses in explaining why they don’t call Trump a liar in their news pages.

But not all of the Post’s competitors have taken that path. The New York Times has twice called out Trump for using a “lie” on its front page -- in September when referencing his “‘birther’ lie,” and in January when discussing his “lie about [the] popular vote.”

Both statements were among those Sanders highlighted as lies.

It doesn’t make a lot of sense to demand that politicians adhere to the same standards for rhetoric as news reporters. It makes even less sense to say that they should adhere to the standards of the Post and not that of the Times.