Dallas: President Barack Obama implored Americans of all races to show more unity and understanding as he addressed an emotional memorial for five slain policemen in Dallas on Tuesday (Jul 12).

The president, accompanied by First Lady Michelle Obama, leaned heavily on scripture as he ministered to a country stunned by gun violence and torn asunder by race and politics.

‘I know that Americans are struggling right now with what we’ve witnessed over the past week,’ he said.

A succession of shootings, each racially charged, has led to a sense that ‘the deepest fault lines of our democracy have suddenly been exposed, perhaps even widened,’ Obama said.

‘I’m here to say we must reject such despair. I’m here to insist that we are not as divided as we seem.’

From Charleston to Orlando to last week’s ambush in Dallas, by a black gunman out to kill whites in retribution for police violence, the past year has seen a torrent of slaughter motivated by hate.

Each week seemingly brings new shaky footage of a police officer shooting dead a black American - images that quickly go viral and revive tough questions about race and policing.

Obama’s speech included a frank admission that his own efforts to tackle violence, guns and racism had come up short.

‘I have spoken at too many memorials during the course of this presidency,’ he said with uncommon candor. ‘I’ve seen how a spirit of unity born of tragedy can gradually dissipate.’

‘I’ve seen how inadequate words can be in bringing about lasting change. I’ve seen how inadequate my own words have been.’

‘We’ve heard prejudice’

Eight years ago, Obama’s rhetorical prowess made him America’s first black president and raised hopes that the country could overcome deeply entrenched societal divides.

Tuesday’s memorial service showed a weary president whose hopes for change had been thwarted.

The way out, Obama said — suggesting work that will continue beyond his presidency — was for Americans to open their hearts to each other.

Black Americans protesting police racism, he said, must understand how hard the police’s job can be.

‘You know how dangerous some of the communities where these police officers serve are. And you pretend as if there’s no context?’

But Obama also challenged a mostly-white police force and white Americans at large to admit that while the edifice of legalised racism had gone, prejudice remained.

‘We have all seen this bigotry in our own lives at some point,’ he said. ‘We’ve heard it at times in our own homes. If we’re honest, perhaps we’ve heard prejudice in our own heads and felt it in our own hearts.’

‘We flood communities with guns’

That call for unity was echoed by Republican former president George W. Bush.

‘Too often we judge other groups by their worst examples, while judging ourselves by our best intentions,’ said the Dallas resident.

But Obama also made a call for Bush’s fellow Republicans to realise the cost of their opposition to gun control and spending on mental health and drug treatment.

‘We allow poverty to fester so that entire neighbourhoods offer no prospect for gainful employment,’ Obama said pointing to string of causes for violence.

‘We refuse to fund drug treatment and mental health programmes. We flood communities with so many guns that it is easier for a teenager to buy a Glock than get his hands on a computer or even a book.’

Earlier a black Dallas trauma surgeon Brian Williams, who treated several police officers, gave poignant voice to the fissures that have shaken the country.

He spoke of buying ice cream for a cops so that his young daughter could see him interacting normally with the police — and not grow up with the same fears he has.

Addressing police, he said: ‘I support you, I will defend you and I will care for you. That doesn’t mean that I do not fear you.’

America, Black and Blue

Last week, the fatal police shootings of two black men, Alton Sterling in Louisiana and Philando Castile in Minnesota, prompted nationwide anger, with thousands of protesters taking to the streets from coast to coast.

They also seemingly triggered the deadly rampage in Dallas by black Afghanistan war veteran Micah Johnson, as a protest against police brutality was wrapping up.

Johnson, 25, used a high-powered rifle to kill five police officers and wound nine others in a sniper attack late Thursday. Two civilians were also hurt.

He told negotiators before he was killed that he wanted to murder white cops in revenge for the black deaths.

The memorial paid a poignant tribute to the fallen ‘peacemakers in blue’ Brent Thompson, Patrick Zamarripa, Michael Krol, Lorne Ahrens and Michael Smith.

Each officer was represented by an empty chair in the auditorium, each adorned with a folded US flag and officer’s cap.