(CNN) President Donald Trump probably isn't going to be heckled at a restaurant any time soon -- since when he does go out to eat, he usually owns the place.

And he's no stranger to a good old-fashioned boycott, having called for boycotts on media organizations and the NFL and been the subject of boycott campaigns as a candidate

But he's sticking up bigly for Sarah Sanders, his press secretary who was asked to leave a restaurant in Lexington, Virginia, and then tweeted about it.

Trump answered the incivility against Sanders with an incivility of his own, criticizing the restaurant's cleanliness.

"The Red Hen Restaurant should focus more on cleaning its filthy canopies, doors and windows (badly needs a paint job) rather than refusing to serve a fine person like Sarah Huckabee Sanders," Donald Trump tweeted. "I always had a rule, if a restaurant is dirty on the outside, it is dirty on the inside!"

As this episode shows, we seem to be in a moment of degraded discourse. Which should surprise exactly no one in a time when the President uses the the imagery of invaders and infestation to describe immigrants and those who oppose him continue to treat his presidency as post-apocalyptic.

Warlike language is going to get nasty.

Rep. Maxine Waters encouraged members of the Trump opposition to essentially play a little dirty to make life difficult for people who work for the President.

"Let's make sure we show up wherever we have to show up. And if you see anybody from that Cabinet in a restaurant, in a department store, at a gasoline station, you get out and you create a crowd. And you push back on them. And you tell them they're not welcome any more, anywhere. We've got to get the children connected to their parents," Waters said at the Wilshire Federal Building, according to video of the event.

Democrats like House Minority Leader Nancy Pelosi called Waters' statements "unacceptable," but blamed it all on Trump's lack of civility.

Trump, by the way, fired back at Waters, too, saying on Twitter she was encouraging violence and calling her "low IQ" and shooting back what seemed like an invitation for his own supporters to heckle her. "Be careful what you wish for Max!"

Sanders ignored her own boss' broadside when she opened her briefing with reporters Monday talking about being asked to leave the restaurant and also an attack against first lady Melania Trump by Peter Fonda on Twitter last week.

"Healthy debate on ideas and political philosophy is important, but the calls for harassment and push for any Trump supporter to avoid the public is unacceptable," she said at Monday's press briefing. "America is a great country and our ability to find solutions despite those disagreements is what makes us unique."

A good amount of this tone has sprung from the President's Twitter account. He's encouraged scorched-earth opposition, particularly against the news media.

A large majority thinks civility has taken a trip out of town in the Trump years. Back in November of 2017 a Marist poll asked , "Since Donald Trump was elected president in 2016, do you think the overall tone and level of civility in Washington between Republicans and Democrats has improved, stayed the same, or gotten worse?" Sixty-seven percent of Americans said it had gotten worse, and that included 60% of Republicans.

And it should be no surprise that as activists and media organizations use ever more intense rhetoric to describe the actions of the President; when families are literally being separated at the border, that civility should be hard to maintain.

And that's why Trump administration officials and staffers, even before Waters' statements, have recently been:

There's obviously a big difference between not being able to get a date and being publicly called out by members of your church. But if there's a sliding scale of incivility, there's space on there for a lot of things.

If you use language of war to describe undocumented immigrants as invaders trying to take over the country, you will likely get a militant response from people who feel very strongly that immigrants are not an invading horde.

A good example of how the sliding scale of incivility can affect a Trump administration official is Vice President Mike Pence.

When he was singled out and lectured in the opening days of the Trump administration by the cast of the Broadway musical Hamilton, that was done mostly respectfully. They were asking him to pay attention to people afraid of the new administration. But those were early days. Pence stayed silent and Trump went after the Hamilton cast on his behalf.

JUST WATCHED Pence leaves NFL game over anthem kneeling Replay More Videos ... MUST WATCH Pence leaves NFL game over anthem kneeling 01:45

Pence was on the other side of the equation when he walked out in disgust from an NFL game due to athletes kneeling for the National Anthem -- that should probably go on the incivility scale too.

And with every Trump tweet and increasingly provocative policy statement that seems designed to divide the electorate, the civility continues to slide.