“Nothing matters.”

It’s a popular and versatile phrase that can be reassuring, a reminder that despite how overwhelmed you feel, nothing matters so go ahead and enjoy that fourth doughnut.

It can also be discouraging, lamenting the feeling that while a precious few are attempting to keep order, the great many aren’t and so nothing matters.

Regardless, it’s no coincidence it’s become so trendy. Nihilism is back, big time.

Nihilism is as old as time itself — it’s at least as old as the first time a dinosaur spotted a giant fireball hurtling toward Earth and thought, “Why did I bother tidying up the bog today?”

There’s cosmic nihilism: The universe is indifferent to your suffering. There’s existential nihilism: You are insignificant, and life has no meaning. There’s political nihilism: All political systems and the values supporting them must be destroyed.

But it’s not the theories of Immanuel Kant, Friedrich Nietzsche or Soren Kierkegaard that I want to dwell on — because, if nothing truly matters, life is short and who has the time?

Rather, I draw your attention to a cartoon dog.

“On Fire” is a webcomic-turned-meme by KC Green published in 2013. In it, a dog sits at a kitchen table as flames engulf the room. “This is fine,” he says. “I’m okay with the events that are unfolding currently.” As his arm is incinerated, he says, “That’s okay. Things are going to be okay.” Finally, his face melts off.

Dark? Yes. Apropos in 21st century America? Definitely.

If it increasingly feels like nothing matters and this isn’t fine, there’s a good reason. We have utterly devalued and distorted accountability to the point of extinction. We’ve stopped demanding it and we’ve stopped believing in it at nearly every level of socio-political experience.

To wit, the political class in America has been failing up for decades. Whether it’s illegal wars, a housing crisis and recession, a now trillion-dollar deficit, systemic inequality and injustice, corruption and graft, it’s hard to see how any of this has been accounted for. Many of the same folks are in power still; politicians are primaried not for failing to do their jobs but for failing purity tests that only a few care about. When a majority of Americans no longer feels like the two parties represent them, it’s easy to believe nothing matters.

Cancel culture is also nihilistic. When a single misused word or years-old mistake can get a person fired and castigated out of civil society — but another person’s lifetime of horrific deeds is either ignored or rewarded with more airtime, power, influence and clout — does anyone truly believe this imbalanced system of public accountability is serving us well?

In right-wing politics, the new nihilism means accountability is relative, which might as well make it meaningless.

“There is no question former President Trump bears moral responsibility,” says Sen. Minority Leader Mitch McConnell, of Trump’s role in the violent insurrection on the U.S. Capitol. But he and all but seven Republican senators voted to let Trump off the hook.

In the words of Sen. Mike Lee, Trump deserved a “mulligan.” For Sen. Ron Johnson, it was actually Speaker Nancy Pelosi’s fault. Fox News host Laura Ingraham blamed, in part, actor Steve Carrell.

Now, the Republican lawmakers who voted to convict are being censured back home. It’s precisely their efforts to hold Trump accountable that make them the heretics within their own party. Nothing matters.

Republican voters, too, have simply stopped caring so much about the things they used to care so much about. The right used to make arguments for life, morality, family values, the Constitution, law and order. Enter Trump-supporting evangelicals, police-attacking rioters, the conspiracy theory QAnon crew. Enter Roy Moore, Joe Arpaio, Marjorie Taylor Greene and Lauren Boebert. Yes, this is fine.

There’s no current equivalency on the left. Democrats are imperfect but uninterested in burning the place down.

New York Gov. Andrew Cuomo is inexplicably defending his handling of COVID-19 nursing home data, despite reports that he intentionally under-reported deaths for fear they’d be “used against” him. The goodish news is that lawmakers from his own party are now demanding he be held accountable — a reckoning most on the right have refused to ever do with Trump, and likely never will.

When we can’t believe in accountability, we believe that nothing matters. When we believe nothing matters, we disengage, or worse, join self-destructive causes and cults. We stop believing in the ties that bind. Ultimately, this new nihilism is corrosive and unsustainable.

In short, this isn’t fine.

S.E. Cupp is the host of "S.E. Cupp Unfiltered" on CNN.