On Jan. 28, 1986, President Ronald Reagan was supposed to deliver the State of the Union.

Instead, he made a very different address to the nation that day, one that would transform the role of president, making it mandatory thereafter that presidents serve as consoler-in-chief.

Hours earlier, the Challenger space shuttle exploded with seven on board, including teacher Christa McAuliffe. McAuliffe's presence meant that millions of schoolchildren were watching that morning live. Reagan speechwriter Peggy Noonan, who drafted the speech, has said she knew the remarks needed to appeal to young and old. The last line would put the address in the history books.

"We will never forget them, nor the last time we saw them, this morning," Reagan said with a somber glint in his eye and an eyebrow raised, "as they prepared for their journey and waved goodbye and slipped the surly bonds of Earth to touch the face of God."

Speeches after tragedies present a special challenge for American presidents. It's one President Trump faces Tuesday in Texas, where he is set to witness the devastation left by Hurricane Harvey. The historic storm has dumped feet of rain on Houston and surrounding areas, leaving several reported dead so far and many more trapped, as the rains have yet to cease.

This will be Trump's first test as consoler-in-chief, and it's not a role he has much experience with. Empathy is not what this president is known for.

"After a large natural disaster, the presidents who have the most success are the ones who express the right mix of compassion and competence," said Brian Jones, a veteran political adviser, who worked on the 2004 Bush campaign and at the Republican National Committee. Trump has "had challenges, at times, showing the right level of compassion and showing the right level of competence, too. He's resonating with the base, but he hasn't broadened it out."

Trump took one trip to a disaster area as a candidate for president a year ago. He helped distribute a truckload of supplies in Louisiana for victims of the worst flooding since Superstorm Sandy. But the event wasn't much more than a photo op.

"It's a great place," Trump said then. "I've had a great history with Louisiana. They need a lot of help. What's happened here is incredible. Nobody understands how bad it is. I'm just here to help."

As president, more will be expected of him Tuesday.

Looking to presidents in times of tragedy

American presidents are looked to as parental figures, to be unifying moral guides, especially in times of crisis.

Back to Lincoln at Gettysburg, presidents have used speeches to steel resolve in times of crisis.

Roosevelt told Americans after Pearl Harbor "their righteous might will win through to absolute victory."

After Kennedy was assassinated, Johnson urged the country to persevere. "Let us continue," he said.

Reagan's Challenger speech, because of the writing and delivery, historians say, is the marker for when Americans then expected their presidents to feel their pain after tragedies.

George W. Bush, standing on the rubble of ground zero after Sept. 11, bullhorn in hand, channeled the country's defiant anger and said the people responsible "would hear all of us soon."

Bill Clinton tried to comfort and reassure in 1995 after the Oklahoma City bombing. "You have not lost America, for we will stand with you," he said, adding an anecdote about a dogwood tree planted at the White House in honor of the children who died. "My friends, a tree takes a long time to grow," he said, "and wounds take a long time to heal, but we must begin."

Barack Obama made many speeches after tragedy and even sang "Amazing Grace" in church after parishioners were killed in Charleston, S.C.

Presidents need to understand the optics, own the message and empathize, but after natural disasters, words are not enough. They need to understand the role and capabilities of the federal agencies at their disposal.

The obvious parallel the Trump administration is trying to avoid is Bush's response to Hurricane Katrina. He failed on the optics and substance.

A photo of Bush looking out the window of Air Force One to survey damage made him look aloof — even though, as his White House pointed out, Bush had good reason not to land Air Force One, and the president wanted an aerial view to capture the full magnitude of the devastation.

On substance, Bush's praise of FEMA administrator Michael Brown, whom he said was doing "a heck of a job," was disconnected from the reality on the ground.

"His [Trump's] talents, he says, are organization and deal-making," said Barbara Perry, director of presidential studies at the University of Virginia's Miller Center. "Will he be able to do that at the federal level with the government coordinating with nonprofits, NGOs and state government to help people and alleviate the suffering? Of all places, this is where his business experience he has been touting has to come to the fore now and show real results."

Complicating matters for Trump, he is at a low point in his presidency. His poll numbers are suffering, and Trump's response to racist violence in Charlottesville, Va., was widely panned.

Perry sees a parallel in this moment to Clinton and Oklahoma City in 1995. Clinton was coming off a devastating midterm defeat with Democrats losing the House for the first time in 40 years.

"Bill Clinton was being viewed as diminishing, diminished and shrinking," Perry said, noting that the broadcast networks had even turned down a Clinton request to hold a prime-time news conference. He had his back up against the wall as does Trump."

But Clinton's Oklahoma City memorial speech helped burnish his reputation as a president who could feel your pain and helped his presidency rebound.

"Clinton did that so well," Perry said. "It became cliché that Clinton could feel people's pain, but he was good at that. And it's not just optics, but people believed he really did feel their pain."

In other words, it's not just the words but sincerity. That's something Trump has struggled to convey beyond his base. Trump seems most comfortable in his unscripted, wide-ranging rallies, not in scripted, teleprompter-read remarks.

"He made a connection to people having a tough time," Jones said of Trump's campaign. "He knows how to relate to people. Can he turn that on again? Can he express the right level of empathy? He did a good job with people disaffected, frustrated with the system. It was an 'I understand your pain' type of thematic. He needs to tap into that kind of sentiment," but for more than just his supporters.

What Trump needs to do

Showing up is the first, right step for Trump, strategists say.

"President Trump is doing the right thing by going to Texas," said Alex Conant, a Republican strategist who worked for Marco Rubio's presidential campaign. "Nothing can replace seeing a disaster firsthand."

But Trump needs to remain singularly focused and not get distracted by side controversies or make it too much about himself.

"Whenever a president visits a disaster site or meets with victims of a tragedy, it's important that he not make the visit about him," Conant said. "Shifting focus away from the real heroes and victims would not only be counterproductive, but could quickly become a political problem. Keep the focus on those most impacted by the storm and what can be done to help. The country is united behind the people impacted by this storm. As terrible as the storm is, hopefully Trump can channel our nation's unity and goodwill into something positive."

Kevin Madden, a former senior adviser to Mitt Romney's presidential campaigns, echoed that.

"If you look back at the 'big moments' that occurred with presidents dealing with tragedies or crises, the common element was the ability to offer reassurance, providing a watchful nation a sense of calm and unity of purpose," Madden said. "For Trump, the key here will be blocking out distractions and keeping his words and deeds squarely focused on the rescue missions, the humanitarian relief and economic recovery that needs to take place. It can't be about him or taking credit, but instead it has to be focused on the task at hand and the plight of all of those affected by the storm."

For many, this crisis is far from over, and that means the federal government's response will be scrutinized beyond early remarks from the president.

"Those remarks should be inclusive, healing and aspirational in terms of focus on the future," GOP strategist Phil Musser said. But Trump also has to show "command of the situation — the operational tick-tock — that demonstrates that the leader of the government is in charge, focused on the challenge and resolving it as quickly as possible, and on top of things. Being on the ground, at the crisis, and meeting with key leaders — while not letting the trappings of the traveling White House mess up recovery — is the right thing to do. Message: We care!

Copyright 2017 NPR. To see more, visit http://www.npr.org/.