There is a movie I’m looking forward to seeing when it comes to Washington. It seems quite relevant to America today. It’s about what can happen in a democratic society when politicians go too far, when they not only stand mute when hateful words that cross civilized redlines suddenly become part of the public discourse, but, worse, start to wink at and dabble in this hate speech for their advantage.

Later, they all say that they never heard the words, never saw the signs, or claim that their own words were misunderstood. But they heard and they saw and they meant. Actually, I don’t need to see the movie, because I lived it. And I know how it ends. Somebody gets hurt.

The movie is called “Rabin: The Last Day.” Agence France-Presse said the movie, by the renowned Israeli director Amos Gitai, is about “the incitement campaign before the 1995 assassination of Prime Minister Yitzhak Rabin” and “revisits a form of Jewish radicalism that still poses major risks.” This is the 20th anniversary of Rabin’s assassination by Yigal Amir, a right-wing Jewish radical.

“My goal wasn’t to create a personality cult around Rabin,” Gitai told A.F.P. “My focus was on the incitement campaign that led to his murder.” Sure, the official investigating commission focused on the breakdowns in Rabin’s security detail, but, Gitai added, “They didn’t investigate what were the underlying forces that wanted to kill Rabin. His murder came at the end of a hate campaign led by hallucinating rabbis, settlers who were against the withdrawal from territories and the parliamentary right, led by the Likud (party), already then headed by Benjamin Netanyahu, who wanted to destabilize Rabin’s Labor government.”

The film, A.F.P. said, “relied on documents, photos and videos, particularly from the months before Rabin’s assassination, including those showing speeches from politicians such as Netanyahu at rallies against the Oslo accords, where Rabin was depicted in a Nazi uniform.”

I hope a lot of Americans see this film . for the warning it offers to those who ignore or rationalize the divisive, bigoted campaigns of Donald Trump and Ben Carson and how they’re dragging their whole party across civic redlines, with candidates saying, rationalizing or ignoring more and more crazy, ill-informed stuff each week.

Trump actually launched his campaign on June 16 with a message of polarization, saying: “When Mexico sends its people, they’re not sending their best. … They’re sending people that have lots of problems, and they’re bringing those problems with us. They’re bringing drugs. They’re bringing crime. They’re rapists. And some, I assume, are good people.”

The Washington Post’s Fact Checker column gave him four Pinocchios, its highest rating for not telling the truth, noting: “Trump’s repeated statements about immigrants and crime underscore a common public perception that crime is correlated with immigration, especially illegal immigration. But that is a misperception; no solid data support it, and the data that do exist negate it.”

And then Trump insulted John McCain, saying he was only a war hero because he got captured, adding, “I like people that weren’t captured, O.K.?” McCain spent five and a half years as a P.O.W. in Vietnam and was repeatedly tortured and had his bones broken. As CNN reported, “Trump, meanwhile, received four student deferments and one medical deferment to avoid serving in the Vietnam War.”

What does it mean to impugn a man who has sacrificed so much for his country? It means you can smear anyone.

Last week another redline was crossed. At a Trump town hall event, the first questioner began: “We got a problem in this country. It’s called Muslims. We know our current president is one. We know he’s not even an American. But anyway. We have training camps brewing where they want to kill us. That’s my question. When can we get rid of them?”

Trump responded: “A lot of people are saying that bad things are happening out there. We’re going to be looking into that and plenty of other things.”

Trump could have let the man ask his question and then correct his racist nonsense, without blocking his free speech, which is exactly what McCain did in a similar situation. Instead, he later said it was not his place to defend Obama. As someone who aspires to be president it is his place to defend the truth, but since Trump himself has been the source of so much birther nonsense about Obama, I guess that would be hard. Instead he tweeted: “Christians need support in our country (and around the world), their religious liberty is at stake! Obama has been horrible, I will be great.”

And then, like clockwork, Ben Carson saw Trump blurring another civic redline and leapfrogged him. Carson stated, “I would not advocate that we put a Muslim in charge of this nation.”

So a whole faith community gets delegitimized and another opportunity for someone to courageously stand up for what’s decent is squandered. But it will play well with certain voters. And that is all that matters . until something really bad happens. And then, all of it . the words, tweets, signs and boasts . will be footage for another documentary that ends badly.