A tweet sent by NBC News reporter Katy Tur during a Donald Trump rally in Atlanta on Sunday is making the rounds on the Internet — held up as the perfect encapsulation of a very imperfect dynamic between the Republican presidential front-runner and his supporters when it comes to the press.

Fox News host Megyn Kelly — Trump’s favorite media target — sounded fed up with such behavior in a response, as did Tur’s NBC colleague, Chuck Todd.

But it is Tur’s overlooked follow-up tweet that really captures the state of affairs in just three words.

That’s the thing, right? This is the new normal. What once seemed shocking is now routine. Tur (“little Katy,” in Trump’s belittling parlance) sounded jaded as she delivered a dispassionate play-by-play account of the latest rhetorical assault on the news media, as if she couldn't muster any more outrage.

And really what's left after Trump has already mocked a reporter's physical disability and joked about killing journalists?

Numbness might be the real danger here. Sure, there are other reasons to be concerned about the way Trump and his crowds interact with reporters. He has created an environment in which it is difficult and uncomfortable to do critical journalism, which — love it or hate it — is an important piece of our democracy. Even Trump's most passionate followers should want to know whether he's really the conservative crusader for American greatness that they hope he is.

There's always the possibility that someone in the crowd will take things too far — like, physically — and people will get hurt. It's all too easy to imagine.

But the long-term risk is that media producers and consumers become so desensitized to this kind of hostility that it permanently lowers the standard of civil discourse.

For now, Trump is generally considered a unicorn — a candidate who gets away with things no one else could. But what if he isn't? What if he's a preview of a political future in which facts and respect don't matter, a future in which voters have nothing but scorn for the journalists trying to help them make informed decisions?

Many in the media have been asking: When is enough, enough? But what if the answer is "never?"