As we once again mourn the slaughter of innocent people by a man wielding an assault rifle, as we hope we can believe assurances that there are no more pipe bombs in the mail, as we talk about our thoughts and prayers while knowing how ineffective that sounds yet again, some voices from the scene of the latest carnage offer guidance and inspiration.

The leaders of Bend the Arc in Pittsburgh, a local part of a national organization that describes its members as progressive Jews fighting for the “soul of the nation” have written an open letter to President Donald Trump to say, “you are not welcome in Pittsburgh until you fully denounce white nationalism.”

They make their case with eloquence, passion and facts.

“For the past three years your words and your policies have emboldened a growing white nationalist movement. You yourself called the murderer evil, but yesterday’s violence is the direct culmination of your influence.”

They are not alone in this. Much of the reporting and commentary concerning the attack Saturday morning at the Tree of Life synagogue which killed 11 and wounded six has focused on other times when the president had a chance to denounce hatred in general and anti-Semitism in particular yet has not only failed to do what all previous presidents have done as a matter of course in times of trouble but has gone out of his way to comfort those whose rhetoric inspires such actions.

When neo-Nazis and others from the alt-right marched in Charlottesville, Va., last year, carrying torches and chanting “Jews will not replace us,” the president refused to condemn those who openly espoused white supremacy.

“I think there is blame on both sides,” he said.

As the leaders of Bend the Arc wrote, “Our Jewish community is not the only group you have targeted. You have also deliberately undermined the safety of people of color, Muslims, LGBTQ people, and people with disabilities. Yesterday’s massacre is not the first act of terror you incited against a minority group in our country.”

And as the crucial midterm elections draw closer, the president and his supporters are not only ignoring the chance to bring the nation together, they are intent on driving us further apart especially with talk of the caravan of migrants fleeing poverty and persecution in Central America and making their way through Mexico and approaching the southern border of the United States.

Tom Steyer, the liberal California billionaire who was among those to whom rabid Trump supporter Cesar Sayoc tried to mail a bomb, criticized the president over the weekend and drew a typical Trump response:

“He comes off as a crazed & stumbling lunatic who should be running out of money pretty soon.”

Those who wrote the open letter to the president must know that he is unlikely to follow their suggestion and “commit yourself to compassionate, democratic policies that recognize the dignity of all of us.”

But the rest of us can, and that includes those who voted for Donald Trump. After this weekend of bombs and slaughter it is hard to understand how any can still excuse his behavior.