The United States is reeling from a week of violence allegedly perpetrated by white-male terrorists. And the President seems more worried about his hair.

On Sunday, Australian time, a man allegedly yelled “all Jews must die” before shooting dead 11 people and wounding six others at Tree of Life Synagogue in an inner suburb of Pittsburgh, Pennsylvania.

It was likely the deadliest single attack on Jews in US history, according to The Anti-Defamation League. It followed what could be the largest attempted assassination of US political leaders ever – a string of mail bombs.

The Jewish families had gathered at Tree of Life for a bris, the ceremony when a Jewish baby boy is circumcised. Hatred interrupted joy.

The gunman was reportedly armed with a military-style AR-15 assault rifle and several handguns, according to witnesses. The firepower was so formidable that four police officers who rushed to the scene were wounded.

Federal prosecutors have charged the 46-year-old suspect, Robert Bowers, with 29 criminal counts including 11 counts of use of a firearm to commit murder during and in relation to a crime of violence. He could face the death penalty.

The suspects: Robert Bowers (left) in the Pittsburgh shooting, Gregory Bush for Louisville shooting, and alleged mail bomber Cesar Sayoc.

After his arrest, Bowers told police that Jews were committing genocide and he wanted them all to die.

A pair of brothers, a married couple and a 97-year-old woman were among his victims.

Past presidents would have immediately suspended politicking and given convincing condemnations of violence.

Mr Trump issued a condemnation, of sorts, yet he then criticised the synagogue for not having “some kind of protection”.

He then refused to cancel a planned political rally. Instead, he complained to the crowd that the “very unfortunate news conference”, where he commented on the synagogue killings, had got his hair wet.

“The wind was blowing and the rain and I was soaking wet, and that’s what I ended up with today,” he told the crowd, pointing to his hair. They cheered.

“And I said, maybe I should cancel this arrangement, because I have a bad hair day. And the bad news, somebody said actually it looks better than it usually does.”

Here's the video. Trump jokes that he considered canceling his speech to FFA because his hair got wet while talking to reporters (about the mass shooting in Pittsburgh). pic.twitter.com/wLb4hpERgF

— Kyle Griffin (@kylegriffin1) October 27, 2018

The President’s jokes about his appearance, on the day 11 people were shot dead for their religious beliefs, did nothing to alleviate suspicions that Mr Trump cared little about the wave of violence sweeping the US –let alone his possible role in stirring it up.

Unusually, the suspected synagogue shooter, Robert Bowers, 46, was taken alive, meaning authorities will have the chance to ask: ‘Why?’

It is a question reverberating across the nation. Days earlier, a White Supremacist allegedly killed two black men at a grocery store in Louisville, Kentucky.

And a string of homemade bombs mailed to vocal opponents of President Donald Trump have been traced back, according to police, to outspoken Trump supporter Cesar Sayoc, whose van was emblazoned with pro-Republican and anti-Democrat slogans.

The intended recipients of the potentially explosive manila envelopes were senior Democrat politicians, a billionaire Democrat donor, and “fake news” CNN.

A theory gaining support is that the atmosphere of hatred, intolerance and name-calling – led by Mr Trump but also fuelled by some of his opponents – has erupted into violence.

Former vice president Joe Biden, a leading Democrat and potential candidate in 2020, called for unity.

“This country has to come together,” he said earlier in the week, amid the mail bombing scare.

“Fear stokes bad behaviour. Personal attacks stroke fear,” he added. “This is not America. This is not who we are.”

Mr Trump’s preferred hypothesis was that it was journalists, his favourite foes, who were to blame.

“A very big part of the anger we see today in our society is caused by the purposely false and inaccurate reporting of the Mainstream Media that I refer to as Fake News,” he said on Friday.

“It has gotten so bad and hateful that it is beyond description.”

As he boarded Air Force One to fly to the political rally, fresh from getting his hair wet, Mr Trump dropped his open umbrella at the top of the steps, seemingly unable to fold it and carry it inside.

pic.twitter.com/FYUlFTcB9I

— Jon Wurster (@jonwurster) October 27, 2018

The umbrella sat there, upside down, blowing in the wind until a secret service agent picked it up.

Donald Trump may find it harder to walk away from the complex storm  of division that is battering his nation.

By Jackson Stiles and Andrew Tate