The e-mail arrived at 6:35 a.m. Friday from a White House press aide. The subject line was urgent: “For pool report — to send asap.”

Inside was a one-sentence message: “From Jay Carney: The President was notified of the shooting in Aurora, Colorado by his Homeland Security Adviser, John Brennan at 5:26 a.m. ET this morning.”

The presidential campaign bubble can be among the most choreographed of places — where even spontaneous “off the record” stops are planned in advance and reaction to the daily political debate is scripted for maximum effect.

That is why Friday was such a jolt for President Obama and his traveling campaign caravan. As the “pool reporter” assigned Friday to shadow the president — at his hotel, in his motorcade, on Air Force One — and send reports to the national White House press corps, I saw first-hand how an operation even as large and experienced as Obama’s struggled to comprehend, and react to, the fast-breaking news of the movie theater massacre.

On this day, in an election season full of daily competition, the Obama White House’s “rapid response” would mean more than simply fighting back against negative Web videos from the president’s opponent. It was a day when politics would give way to pathos, and a president often described as cold and aloof would try to deliver a response calibrated to be both empathetic and authentic.

When the big, unexpected story breaks — Columbine, Hurricane Katrina, 9/11 — all eyes turn first to the crime scene, and then slowly but directly to the leader of the United States. When did the president learn of the grisly details, how did he react, what can he do about it — and how will he tell it to us?

That’s what everyone wants to know.

So the White House scrambled to tell us. Air Force One flew from Palm Beach, Fla., where Obama had spent the night during a two-day campaign trip to the Sunshine State, to Fort Myers on the Gulf Coast, where the president would make his public remarks about the shooting, and then back home to Washington.

“Important Note On Today,” read the subject line of the second e-mail, which arrived in my inbox at 8:52 a.m. while we were still at the Palm Beach Ritz-Carlton, where the president spent the night. This e-mail was from Jen Psaki, the Obama campaign’s traveling press secretary, who has begun joining Carney, the White House press secretary, on presidential trips to handle campaign-related news.

“The President will address the tragedy in Aurora, Colorado in shortened remarks in Ft Myers, Florida this morning,” Psaki wrote, the first sign that the day’s itinerary, which included rallies in Fort Myers and Orlando, would eventually be jettisoned.

Just a day earlier, a campaign aide had leaked to reporters that Obama would go on the attack Friday, using his Florida speeches to finally hit back at Republican rival Mitt Romney. The presumptive GOP nominee has lambasted the president for using the phrase “you didn’t build that” while talking about business entrepreneurs. Obama was arguing that government helps businesses, but Romney has questioned Obama’s commitment to free enterprise.

Obama will “counterpunch Mitt Romney’s out-of-context attack,” the campaign aide had said.

Now, Psaki was saying, Obama would pull his punches. As the president’s motorcade left the Ritz for the airport, the Obama campaign canceled the Orlando stop entirely. And a short time later, Psaki announced that the campaign had pulled all “contrast ads” — a euphemism for the ruthlessly negative ads that both sides have aired relentlessly — off the air in Colorado out of respect for the grieving. The Romney campaign did the same.

At the Palm Beach airport, Obama’s limousine pulled up on the tarmac next to Air Force One, and the president boarded his plane. It was a scheduled 35-minute flight to Fort Myers. During it, the president phoned Aurora Mayor Steve Hogan and Colorado Gov. Tom Hickenlooper (D).

Minutes en route, Carney and Psaki appeared under the archway in the press cabin at the rear of the plane, just in front of the kitchen. They would conduct the customary in-flight press gaggle — a briefing on the news of the day. Carney, a half-dozen reporters huddled close to hear him above the hum of the engines, read a hastily prepared statement.

Slowly, the press secretary explained that Obama had gotten a second briefing from Brennan, Chief of Staff Jacob Lew and FBI Director Robert Mueller on the way to the airport. Obama, Carney said, first wanted to be sure the incident was under control and no one else was danger; assured the scene was secure, the president next reacted as a parent, Carney continued.

And then, the press secretary, a father of two, choked up. He cast his eyes down at a piece of white paper in his hand and fought back tears. As a reporter for Time Magazine, Carney, now 47, had been among the small press pool shadowing then-President George W. Bush on Sept. 11, 2001 — when Bush learned of the terrorist attacks in New York and Washington while reading to elementary school students at a school in Florida. He watched the Twin Towers fall while aboard Air Force One, as Bush flew to a military base in Louisiana.

Now, Carney composed himself and moved on, emphasizing that agents had found no links between the Aurora shooter and organized terrorist groups.

Later in the 10-minute gaggle, Carney returned to the point he had not been able to articulate earlier. Obama “mentioned to me how heavy his heart is, the pain he understands the parents and loved ones must be suffering,” Carney said. “Children across America go to movies, as do adults. It’s just a terrible tragedy. He feels that deeply.”

Obama would address this point directly during his seven-minute speech at the Harborside Event Center in Fort Myers. On the trip, Obama had brought his chief speech writer, Jon Favreau, 31, who has helped the president compose his most memorable public speeches.

Now the script would have to be rewritten; Psaki said it was still being prepared aboard the plane. They would dump the well-rehearsed stump speech that Obama has given so often that he has recently begun weaning himself from the teleprompter.

The president’s motorcade pulled up to the convention center. Inside, hundreds of supporters had been waiting for hours. Behind the stage was a large American flag, and red-white-and-blue bunting hung from the rafters. But the ever-present giant campaign banner with the slogan “Forward.” was missing. There was no music playing. A list of introductory speakers was pared down to a single woman, who led the Pledge of Allegiance and then introduced Obama.

The crowd cheered, and hundreds of cellphones were raised to record the moment. But Obama was somber. Chants of “four more years!” broke out here and there, but he did not acknowledge them.

“I know many of you came here today for a campaign event,” Obama began. “But this morning we woke up to news of a tragedy that reminds us of all the ways that we are united as one American family.”

Later, he grew more personal: “I’m sure that many of you who are parents here had the same reaction that I did when I heard this news. You know, my daughters go to the movies. What if Malia and Sasha had been at the theater, as so many of our kids do every day?”

The president led a moment of silence for the Aurora victims and their families. Then he spent 30 minutes greeting supporters and campaign donors backstage before departing.

Two hours later, Air Force One began descending into Washington as a live feed of CNN coverage of the massacre played on the in-cabin televisions. Without warning, Carney reappeared in the press quarters. The press secretary sat down on the floor, in the middle of the aisle, and recited a list of senior officials who would brief Obama on the shooting as soon as the president arrived at the White House.