In the aftermath of the murder of the Rev. Martin Luther King Jr. in 1968, Sen. Robert F. Kennedy, then a candidate for president, went forward with a planned rally at 17th and Broadway in the heart of Indianapolis' African American community. The country had witnessed more than 100 race riots that left at least 83 dead and 1,800 injured the previous summer, and Kennedy knew that news of King's assassination could result in similar violence. Instead, he called for "an effort to understand with compassion and love."

Kennedy's speech is rightfully hailed as one of the great moments of American political rhetoric. His plea was tragically not successful: More than 40 were killed and 2,500 injured in the riots that followed. The Democratic Convention in Chicago was a long clash between police and demonstrators. The Weathermen began their "days of rage" in 1969. The Kent State shootings shocked the nation a year later. Meanwhile, thousands of Americans died in Vietnam: 11,363 in 1967, 16,899 in 1968, 11,780 in 1969 and 6,173 in 1970.

Nevertheless, Kennedy's speech was a heartfelt, deeply moving appeal for healing and love among fellow citizens. Kennedy, who himself was killed two months later, saw all that had occurred, all that loomed and tried to stop it. Read his speech from that night in Indianapolis. Better yet, listen to it.

Then ask if you heard anything approaching that this past week from any corner of the Democratic Party. Kennedy was running for president as a Democrat, but he was very much running against President Lyndon B. Johnson and the Vietnam War. Still, he did not use the tragedy of King's murder to score points. He did not demonize his opponents in the field, Hubert Humphrey and Eugene McCarthy, or his presumptive opponent in the fall, Richard Nixon. He didn't just speak to Democrats or some small slice of Democrats whom he considered "his base." Kennedy spoke to all Americans, especially the deeply traumatized black community, and urged peace and love and healing.

The aftermath of the El Paso, Texas, and Dayton, Ohio, mass murders, both rooted in the malaise and bigotry of our online age on both the fringe left and right, did not summon forth a Kennedy. Every single Democrat missed his or her opportunity to step up, as RFK did, and instead stepped in it, as I noted in Friday's Post "Pundit Power Rankings."

Indeed, almost all of the Democrats chose in this week following a weekend of horrors to pivot their main message of the campaign trail from "Trump and Russia" to "Trump and racism." At least five of the Democratic candidates went so far as to brand President Donald Trump as a white supremacist.

This is repulsive rhetoric - the sort of speech intended to marginalize and exile. It is "basket of deplorable" on steroids, and it says to every Trump supporter: "You, too, are a white supremacist."

I discussed the actual number of "white supremacists" with Hillary Clinton on my radio show in November 2017.

"Of the 62.9 million people who voted for President Trump, do you have a number in your mind that you think are actually white nationalist racists of that 62.9 million, a real number?" I asked. "I don't think there are 100,000 in any given state. I don't think there are a half million in the United States. Do you disagree with me? Do you think there are more than a half million, you know, honest-to-God white nationalists running around the United States?"

"Probably not, no," Clinton responded. "But I think there are people who are unfortunately kind of reverting back to rather virulent attitudes about race in part because I think that it's become 'politically acceptable,' no longer politically correct to try to overcome our own feelings that often block us from seeing each other as fellow human beings. So no, the hardcore people, I agree with you, I don't think that is a very large number." Clinton was right.

I do not believe Trump is a racist, much less a white supremacist. I think the rhetoric of the Democratic candidates is incendiary and dangerous, and also politically self-destructive. It is so absurd as to be laughable but for its repetition.

But they do not wish to argue, debate and persuade. They wish to smear and exclude, and they have exploited this week’s shock and fear to do so. They should turn back. They should follow the example of Bobby Kennedy, as should Trump. We could all listen to Kennedy’s plaintive words of 51 years ago to good effect.

Hugh Hewitt | For The Washington Post

Hugh Hewitt, a Washington Post contributing columnist, hosts a nationally syndicated radio show on the Salem Network. The author of 14 books about politics, history and faith, he is also a political analyst for NBC, a professor of law at Chapman University Law School and president of the Nixon Foundation.