IT HAS been clear for some time that smartphone cameras add a lot to society’s knowledge about what happens in the world. A series of horrible shootings this week in Baton Rouge, Louisiana; in Falcon Heights, Minnesota; and in Dallas, Texas, have once again demonstrated the power of amateur smartphone video to show millions of people shocking events almost in real time. Protest marches and vigils were held in cities nationwide after social media and traditional broadcast television networks circulated images of a police shooting in Baton Rouge in the early hours of July 5th, and in Falcon Heights on July 6th. In the first incident Alton Sterling, a black man, was shot outside a convenience store by two white officers answering a 911 emergency report of a threatening man with a gun. Smartphone images show Mr Sterling, who had for some years sold CDs and DVDs outside the shop, being confronted, forced to the ground, restrained and then—after shouts of “he’s got a gun”—apparently being shot at close range. Though investigators will doubtless have much to ask a conventional eye-witness, the shop’s owner, who said that police reached into Mr Sterling’s pocket and pulled out a gun only after the shooting, many Americans shared the instinctive reaction of Louisiana’s governor, John Bel Edwards, a Democrat, who said he had “very serious concerns” after watching the “disturbing” video.

The immediate aftermath of the second incident, in Minnesota, is captured in a roughly 10-minute video played on the Facebook page of a young Minnesota woman, Diamond Reynolds, as she responds with remarkable self-discipline to a frantic-sounding police officer who has just shot her boyfriend, Philando Castile, in the driver’s seat of his car after a routine traffic stop to inspect a broken rear light. Mr Castile, a school canteen supervisor, was licensed to carry a gun and had told the policeman he was armed. “I told him not to reach for it,” the officer shouts, his gun still pointed at Ms Reynolds, whose four-year old daughter is in a back seat. As if determined to gather evidence in real-time Ms Reynolds tells the policeman: “You told him to get his ID, sir. His driver’s licence.” She adds: “You shot four bullets into him, sir.” Once again, the video seemed to galvanise the state’s governor, Mark Dayton, who said he was “appalled” and called for an investigation to establish what had happened with the greatest urgency, asking: "Would this have happened if those passengers, the driver were white? I don't think it would have."

The third, related tragedy saw five policemen murdered in cold blood by a sniper on the evening of July 7th, as several hundred demonstrators marched peacefully through Dallas to protest against recent police shootings. Officials said the suspected gunman was killed by a bomb of his own making after hours of negotiations ended with a police bomb squad robot being sent to detonate the device. The gunman was named as 25-year-old Micah Xavier Johnson, a black Army reservist trained as a carpenter and mason who had served in Afghanistan. He told negotiators that he was angry about police shootings and wanted to kill white people, especially white police officers. Once again, television screens and social media filled with graphic images of demonstrators fleeing in terror as gunshots first rang out.

In this grim and tense moment, there are some reasons for hope, however. For many leading politicians of right and left reacted with commendable calm to these latest, racially charged shootings. In part, the strikingly measured tones adopted by such very different politicians as Barack Obama, Donald Trump, Hillary Clinton and Paul Ryan surely reflect the peril of the moment. The political landscape already feels as ready to burn as any tinder-dry, drought-stricken forest, so that throwing inflammatory statements around would be as wicked as any act of arson.

But to be optimistic, as Lexington wants to be, many political reactions seemed to bear the influence of something nobler than mere caution. One after the other national figures asked the public to imagine what it might be like to be Ms Reynolds, or any black American wondering if they can trust the police.

That raises a hopeful thought: perhaps through their sheer immediacy and the raw intimacy of their images, today’s ever-present smartphone cameras are not just tools for recording facts, but instruments with a rare power to foster empathy.

Americans might like to cling to that thought as summer temperatures mount, and every week and month seems to bring news of a new mass shooting. For if there is one thing that the country needs right now, is it a supply of empathy deep enough to prevent society from retreating into rival camps of hostility and mutual suspicion, glaring at each other across divides of race, class and ideology.

For sure, some politicians appeared determined to tell Americans that they live in a zero-sum world of conflict. Dan Patrick, the Republican lieutenant-governor of Texas (a powerful post in that state), headed onto Fox News television and launched into a blanket denunciation of all those who protest against any police actions, whether peacefully or not, seeming to assign responsibility to all of them for the murders in Dallas. “I’m sick and tired of those who are protesting our police and putting their lives in danger,” he said, before turning to the images of peaceful protestors in Dallas fleeing the gunshots targeting police. Despite reports that, before the ambush, Dallas police had co-operated with the protestors and supported their right to demonstrate, Mr Patrick called the demonstrators fleeing the sniper “hypocrites.” The protestors “ran the other way, expecting the men and women in blue to turn around and protect them,” he said.

A Republican congressman from Texas, Louis Gohmert, used a TV appearance to slander President Obama, and misrepresent the positions taken by the (admittedly amorphous) Black Lives Matter protest movement. Mr Gohmert ignored the fact that the president has condemned every attack on police officers. On July 8th Mr Obama called the Dallas shootings a “vicious, calculated and despicable” attack on police—a day after urging Americans to be troubled by the shootings in Louisiana and Minnesota, and by the appearance or reality of racial bias that lead communities to distrust the “vast majority of police officers who put their lives on the line to protect us every single day.” Unmoved, Mr Gohmert declared that a “divisive” Mr Obama “always comes out against the cops,” adding—inaccurately—that “this administration has supported Black Lives Matter as even their leaders have called out for killing cops.”

Given such heated rhetoric, it was a welcome relief to see a calm and balanced statement from Mr Trump, the presumptive Republican nominee. While calling for “law and order” on the streets and offering prayers for the murdered police officers, he also said: “the senseless, tragic deaths of two people in Louisiana and Minnesota reminds us how much more needs to be done,” to make Americans feel secure. “Our nation has become too divided,” Mr Trump concluded, urging more “love and compassion.”

Mrs Clinton, the presumptive Democratic presidential nominee, told CNN television that she called on Americans “to do much more to listen to each other,” adding that white people like her should try to put themselves “in the shoes” of black families having to have “The Talk” with their children about how to stay safe and non-threatening during encounters with the police.

Mr Ryan, who as Speaker of the House of Representatives is the country’s most senior elected Republican, gave a short and emotional speech in Congress in which he asked Americans of all opinions not to “let our anger send us further into our corners”. Mr Ryan sought to describe the common ground uniting Republican and Democratic members of Congress whose hearts are with the murdered police and their families, but who also want “a world in which people feel safe regardless of the colour of their skin, and that is not how people are feeling these days.” The Speaker praised the values that brought protestors to the streets of Dallas: “respect, decency, compassion, humanity.”

His call to respect the motives of all sides was echoed by Senator Marco Rubio of Florida, a former Republican presidential candidate now running for re-election to the Senate. Cynics may ascribe Mr Rubio’s mild tone to the diverse population of his home state, and the fact that bombastic Mr Trump trails in the polls there. But his words are worth quoting at length, for they precisely describe how those grainy smartphone images promote fellow-feeling:

Those of us who are not African American will never fully understand the experience of being black in America. But we should all understand why our fellow Americans in the black community are angry at the images of an African American man, with no criminal record, who was pulled over for a busted tail light, slumped in his car seat and dying while his four-year-old daughter watches from the back seat. All of us should be troubled by these images. And all of us need to acknowledge that this is about more than just one or two recent incidents. The fact is that there are communities in America where black families tell us that they are fearful of interacting with their local law enforcement. How they feel is a reality that we cannot and should not ignore.

The 2016 election campaign is not about to turn into a group therapy session. Perhaps partisan flame-throwing will dominate the next few days. But if it does not, some thanks will be owed to those omnipresent watching phones.