"You are a rude, terrible person," President Trump said to a reporter, not to his mirror, earlier this month. This was rich coming from a man who, as president, threatened to beat up a former vice president of the United States, called a porn star "Horseface," and threw rolls of paper towels at hurricane victims.

Nearly a century ago, Emily Post wrote her famous guide to etiquette, which, like every other book that has ever been published, Trump has not read. "To do nothing that can either annoy or offend the sensibilities of others is the principal rule of conduct," Post wrote.

Trump has made a career out of annoying and offending the sensibilities of others. He began his presidential campaign by calling Mexicans rapists and ended it by calling his opponent a nasty woman, whom he vowed to imprison. In the intervening months, he disparaged a POW in public, mocked a disabled person in public, and acted like a mentally disabled person in public.

He fails at the simplest gestures of courtesy, from walking in front of the queen of England to his refusal to fly the flag at half-staff after John McCain's death. At a listening session with survivors of a school shooting, he needed a note card saying "I hear you" to remind himself to pretend to listen to them.

Curiously, Trump's social autism is the source of his appeal. A Pew survey found that what Trump's supporters like most about him is his personality, not his policies. They like his personality more than his policies for the same reason that men like the sex scenes in pornography more than the plots: Vulgarity is the point.

Like many people, Trump is at his worst online. As of July, he had insulted 487 people, places, and things on Twitter. Technology, by separating us from the consequences of our actions, makes incivility easy. The internet is a rude place because it's a safe place. You can fight people without getting punched in the head. Online, the only things that get hurt are feelings and careers.

But offline, people get hurt.

In recent weeks, a group of agitators showed up at Tucker Carlson's house and threatened his family, a man at a country club called Carlson's daughter a "whore" and a "f--king c-nt," and someone dumped a bottle of water on Fox News contributor Kat Timpf's head. Since testifying before the Senate Judiciary Committee in September, Christine Blasey Ford has been harassed so much that she hasn't been able to return to work and has had to move four times. According to the FBI, hate crimes rose 17 percent last year, the third year in a row they've increased.

Trump isn't solely to blame, but he's primarily to blame. He makes mean people meaner and dumb people dumber. The internet gives people a platform to be nasty. Trump gives them a template.

Putative Christian leader Jerry Falwell Jr. tweeted recently, "Conservatives & Christians need to stop electing 'nice guys'. They might make great Christian leaders but the US needs street fighters like @realDonaldTrump at every level of government b/c the liberal fascists Dems are playing for keeps & many Repub leaders are a bunch of wimps!"

Just as Jesus said.

After Trump accused Democrats of voter fraud in Florida (his evidence: "I don't know. You tell me."), Gov. Rick Scott (R-Fla.) and Sen. Marco Rubio (R-Fla.) said Democrats were trying to "steal" an election. Sen. Ted Cruz (R-Texas) joked about locking up his opponent Beto O'Rourke, saying, "Well, you know, there's a double-occupancy cell with Hillary Clinton." Wisconsin Republican Senate candidate Leah Vukmir called Sen. Elizabeth Warren (D-Mass.) "Pocahontas." Sen. Cindy Hyde-Smith (R-Miss.) said she wanted to see a "public hanging."

Lord Moulton, an English judge, noted that a nation's greatness is measured not by compliance with the law but by "obedience to the unenforceable," that is, by its manners. Manners are the tax we impose upon ourselves to get along with each other, to make life more bearable.

Trump is a reminder of how not to behave. To make America great again, ask yourself: What would Trump do? Then do the opposite.