In the first half of the second presidential debate in St. Louis, Donald Trump said that if he won the election, he was "going to instruct the attorney general to get a special prosecutor to look into [Hillary Clinton's] situation," thereby providing millions of viewers with an almost dictionary definition of an un-American moment.

When Thomas Jefferson was elected to the presidency in 1801, it was the first time a political party had transferred power to an opposing party through the political process. He characterized that moment in a letter to a friend as one in which "the order and good sense displayed in this recovery from delusion, and in the momentous crisis which lately arose, really bespeak a strength of character in our nation which augurs well for the duration of our Republic" and took the time to say in his inaugural address that "We are all Republicans, we are all Federalists."

We could use a dose of good sense and order now: For perhaps the first time, the U.S. is considering a candidate for president who not only makes public threats against his political opponents, but also has all but promised to use the power of the presidency to persecute his political enemies. Not only does Trump's disregard for the findings of the justice system transmit a conspiratorial paranoia that could easily spark unrest, it foretells a future in which all Americans should fear dissent.

The FBI looked into Hillary Clinton's use of a private e-mail server and found nothing worth prosecuting; in response, Trump implied the FBI is either lax or corrupt and claimed that the agency must have given Clinton "immunity" in its investigation. In other words, the FBI's finding must be invalid.

And there's more. Angry that the Washington Post has printed negative stories about him and his campaign, Trump threatened Amazon.com founder Jeff Bezos in a May segment with Sean Hannity: "[The Post] is owned as a toy by Jeff Bezos who controls Amazon," Trump said, adding that "Amazon is getting away with murder tax-wise. [Bezos is] using the Washington Post for power so that the politicians in Washington don't tax Amazon like they should be taxed." Bezos, Trump claimed, "thinks I would go after him for antitrust because he's got a huge antitrust problem. Amazon is controlling so much of what they're doing. … What he's got is a monopoly, and he wants to make sure I don't get in." However veiled, the threat was clear: Trump has his sights set on the papers that slight him.

He made as much clear in a February rally in Texas, where he announced he will "open up the libel laws" so that "when the New York Times writes a hit piece which is a total disgrace or when the Washington Post, which is there for other reasons, writes a hit piece, we can sue them and win money instead of having no chance of winning because they're totally protected."

More recently, Trump doubled down on his conviction that the Central Park Five — a group of five young men of color accused of the rape of a jogger in New York in 1989 and exonerated by DNA evidence in 2002 — are nonetheless guilty. At the time, Trump took out a full-page ad in the New York Daily News calling for the return of the death penalty. Still, Trump insisted last week on CNN that the accused are still guilty, calling their exoneration "outrageous."

This kind of thing isn't done. The U.S. may be a country of prison policies that — in some instance — need reform; it may be a country that has passed laws that have needed challenging in the past and some that need to be challenged today; but it is a country of the rule of law, not a country of might-makes-right. Under normal circumstances, it probably wouldn't bear spelling out that we don't threaten the press here, that we consider innocent those who haven't been proven guilty, that we don't use the office of the presidency to punish political adversaries competing for the same role.

Emphasizing that there is a normal way of doing things in the face of something so transparently malevolent lacks the emotional luster of justice done — but worth doing, because in this election it has to be done. Just as basic concepts have to be carefully explained to Trump, just as questions have to be teed up for him, so, too, does the American way of life and what it means to run for president have to be explained to him as well. That the presidential nominee of one of the major political parties has to continually have the fundamentals of American life pointed out to him over the course of his execrable 15-month campaign speaks volumes, and the fact that he's come so close to the highest office in the nation with little grasp of or respect for our country's most basic principles should be disturbing to us all. That he may have done permanent or lasting damage to the self-evidence of these principles should be equally discomfiting.

Trump may like to compliment himself for being a supposedly law-and-order candidate who traffics in the arena of dominance, but America traffics in votes, due process and the rule of law — yesterday, today and tomorrow, regardless of what a thug like Trump says.

Evan Fleischer lives in Boston. He wrote this article for the Washington Post.