An hour’s brisk walk can take you from the Dunker Church, across “the cornfield” and down Bloody Lane all the way to Burnside Bridge — the key locations on the battlefield at Antietam, a little more than an hour’s drive from the U.S. Capitol and scene of the bloodiest single day for the American military in our history.

Some 23,000 in blue or gray were killed or wounded, or went missing during the grueling 12 hours of close combat at Sharpsburg, Md., on Sept. 17, 1862.

When pundits talk of a “cold civil war” in the country, they mark themselves as ignorant of the real thing. Far from real war, the civil tension in the country isn’t even close to 1960s levels of violence, much less the sort of actual war that once convulsed the country in the 1860s. Screaming demonstrators at hearings jar. But they aren’t the Weathermen terrorizing the 1960s, not the Oklahoma City bombing, not the Fort Hood massacre.

Yet.

But some seem to welcome a slide in that direction. “Tell me again why we shouldn’t confront Republicans where they eat, where they sleep, and where they work until they stop being complicit in the destruction of our democracy,” tweeted Ian Millhiser, justice editor at ThinkProgress.

“Because it is both wrong & supremely dangerous,” replied Georgetown Law professor Randy Barnett. “When one side denies the legitimacy of good faith disagreement over policy — as well as over constitutional principle — the other side will eventually reciprocate. Neither a constitutional republic nor a democracy can survive that.”

Princeton’s much-admired political theorist Robert P. George said of the exchange: “Randy Barnett drops a major truth bomb in response to an especially foolish and irresponsible tweet. We’re already in the orange zone of bitterness and hatred of citizens toward fellow citizens. We’re about to enter the red zone. This is how faction destroys democratic republics.”

The daily ratcheting-up of rhetoric is driving people away from ordinary political conversation. It is too freighted with potential for disproportionate responses to talk candidly about such things as one’s views of the Kavanaugh hearings. The intentional release of senators’ home addresses by someone there is reason to believe is a Capitol Hill staffer — “doxing” — is an ominous step in the Millhiser direction. It is a step back toward the tragedy that unfolded only last year when a deranged Bernie Sanders supporter tried to gun down the GOP caucus at baseball practice.

Its cause is the retirement of a Supreme Court justice who was appointed by a Republican president, and his imminent replacement by a Supreme Court justice nominated by a Republican president. Though Donald Trump is not anyone’s idea of a conventional president, Judge Brett M. Kavanaugh is not only extraordinarily qualified but also a deeply conventional choice. So when arguments about process failed, that part of the left that demands power above all other things turned to character assassination.

A vast swath of the public has concluded that the Democrats sat on an explosive charge until the last minute, and they imagine themselves being ambushed that way at work. They don’t want their daughters and sons to live in a society where allegation is conviction.

Throw in an insufferable “Spartacus” (and who doesn’t work with at least one of them) and the never-to-be-topped irony of Sen. Richard Blumenthal (D-Conn.), who falsely claimed service in Vietnam, lecturing Kavanaugh on a common jury instruction of “falsus in uno, falsus in omnibus” — a warning that a witness who lied in one thing can be assumed to have lied about other things — and anger toward every hypocrite present in every citizen’s life begins to bubble. Toss in Michael Avenatti, and a New Yorker article that no other reputable news platform would stand behind as meeting their standards for reporting, and the volcano erupts because Kavanaugh — a thoroughly decent man, an obviously good man — was slimed.

Media elites locked inside “blue bubble” newsrooms don’t see, hear or feel it. Just as they didn’t see, hear, or feel the 2016 volcano’s rumblings either.

There is indeed widespread, genuine sympathy for Christine Blasey Ford. But millions don’t believe Kavanaugh assaulted Ford, though they believe she has been assaulted, and they won’t be eye-rolled into saying otherwise.

The other allegations spitballing out at the judge have caused the country to shudder. So deeply deceptive, manipulative and unfair are the proceedings, they rightly brought forth comparisons with McCarthyism. The Rosenbergs and Alger Hiss didn’t make Hollywood screenwriters traitors, and Harvey Weinstein and Bill Cosby and all the other such alleged predators don’t make the Georgetown Prep Class of 1983 into their accomplices by assertion. Democrats seem to think that the refusal to saddle up with the new Roy Cohns of the left dooms the right. The right is convinced the opposite is true. November will tell.