Donald Trump was properly quick to offer sympathy to those caught up in the Las Vegas horror.

“My warmest condolences and sympathies to the victims and families of the terrible Las Vegas shooting,” he tweeted early on Monday morning. “God bless you!”

A few hours later, he stood sombre and serious to address the nation from the White House. “We are joined together in sadness, shock and grief,” he said, wearing a black suit and a black and white tie. “Our unity cannot be shattered by evil and our bonds cannot be broken by violence.”

The President is going to be making a lot of such comments this week – a week that may prove to be his most testing yet since he entered the Oval Office. On Tuesday, he is to fly to Puerto Rico, where his response to the devastation left by Hurricanes Maria has been criticised by many residents and the mayor of San Juan.

On Wednesday, he will fly to Las Vegas and seek to offer comfort to those whose lives have been utterly torn apart by the massacre, and thank those who rushed to help. At least 58 were killed and more than 500 injured.

Trump was quick to earn praise for his words and manner. John King, CNN’s chief national correspondent, was among those to say that Trump had sounded “presidential”.

Many will feel it is a testament to how low expectations have fallen in regard to Trump’s behaviour that for him to tweet a message of condolence and read resolutely from a teleprompter, is considered exceptional.

There is a pattern into which the events after a mass shooting in the US follow. There is the initial stunned shock, the press conferences by various authorities, the requests to donate blood, the slow trickle of details about the person responsible, and the victims. Then come vigils and marches and acts of remarkable kindness and solidarity.

Barack Obama and Donald Trump reacted to mass shootings quite differently

Then, at some point, come the questions about how to stop such events from happening. Some – like Hillary Clinton – issue demands for greater gun control and take on the power of gun rights groups such as the National Rifle Association. Others insist it is not appropriate time to do so.

Trump is certainly unlikely to raise such questions. Last year, he was very quickly endorsed by the NRA as its candidate for president and the organisation spent $21m (£16m) to help him, made up of $9.6m on adverts and other pro-Trump materials, and another $12m attacking Clinton.

When he was endorsed, Trump told the media: “The Second Amendment is under a threat like never before. Crooked Hillary Clinton is the most anti-gun candidate ever to run for office … She wants to take your guns away. She wants to abolish it.”

Before he reaches the casinos and sunshine of Nevada, Trump will travel to Puerto Rico. Over the weekend – as criticism of the government’s response to the struggling island grew – Trump began a barrage of attacks on Carmen Yulín Cruz, the mayor of San Juan, who had appeared on television sobbing and saying: “We are dying here.”

Las Vegas shooting – in pictures Show all 15 1 /15 Las Vegas shooting – in pictures Las Vegas shooting – in pictures People scramble for shelter at the Route 91 Harvest country music festival after gun fire was heard Getty Las Vegas shooting – in pictures People carry a person at the Route 91 Harvest country music festival after shots were fired David Becker/Getty Las Vegas shooting – in pictures People run from the Route 91 Harvest country music festival after gun fire was heard David Becker/Getty Las Vegas shooting – in pictures A handout photo released via Twitter by Eiki Hrafnsson (@EirikurH) showing concertgoers running away from the scene (C) after shots range out at the Route 91 Harvest festival on Las Vegas Boulevard EPA/Eiki Hrafnsson Las Vegas shooting – in pictures People lie on the ground at the Route 91 Harvest country music festival after hearing gun fire Getty Las Vegas shooting – in pictures A man in a wheelchair is taken away from the Route 91 Harvest country music festival after hearing gun fire David Becker/Getty Las Vegas shooting – in pictures People stand on the street outside the Mandalay Bay hotel near the scene of the Route 91 Harvest festival on Las Vegas Boulevard EPA/Paul Buck Las Vegas shooting – in pictures FBI agents confer in front of the Tropicana hotel-casino after a mass shooting during a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Las Vegas police run by a banner on the fence at the Route 91 Harvest country music festival grounds after shots were fired David Becker/Getty Las Vegas shooting – in pictures An injured person is tended to in the intersection of Tropicana Ave. and Las Vegas Boulevard after a mass shooting at a country music festival Ethan Miller/Getty Las Vegas shooting – in pictures Metro Police officers pass by the front of the Tropicana hotel-casino after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures A woman sits on a curb at the scene of a shooting outside of a music festival along the Las Vegas Strip AP/John Locher Las Vegas shooting – in pictures A cowboy hat lays in the street after shots were fired near a country music festival in Las Vegas Getty Las Vegas shooting – in pictures Las Vegas Metro Police and medical workers stage in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Sheriff Joe Lombardo (2-R) speaking during a press briefing in the aftermath of the active shooter incident on Las Vegas Boulevard EPA

He said the mayor had been persuaded to criticise the government by Democratic politicians and the “Fake News” media. “Results of recovery efforts will speak much louder than complaints by San Juan Mayor. Doing everything we can to help great people of PR,” he said.

Few felt that Trump’s behaviour was appropriate. More were stunned at his willingness to involve himself in a fight with a low-ranking politician, whose island had been left struggling to find fuel, food and clean drinking water. Thin-skinned, immature and vain perhaps, but not fitting of the highest office in the land.

At the while, Trump also appeared to be undermining the diplomatic efforts being undertaken by his most senior diplomat, Secretary of State Rex Tillerson, to negotiate with North Korea.

“I told Rex Tillerson, our wonderful Secretary of State, that he is wasting his time trying to negotiate with Little Rocket Man,” he said. “Save your energy Rex, we’ll do what has to be done!”

Nobody would pretend that seeking to comfort and unite the nation after tragedies – natural or man-made – is an easy task. Barack Obama said he steeled himself every time there was a mass shooting, for he knew he would be obliged to offer words and emotions that were never enough to salve the pain of those suffering.

Trump may surprise everyone. He is a better orator than his critics would admit and in smaller settings he can be personable and warm. If he simply sticks to the script, avoids a fight with Cruz, and seeks to offer support in Las Vegas, his actions will have be deemed presidential.