President Trump has "a fundamentally different conception of the U.S. presidency" than his predecessors, New York Times reporters Maggie Haberman and Jonathan Swan explain in their new book, "Regime Change: Inside the Imperial Presidency of Donald Trump."

Haberman and Swan sat down with "CBS Mornings" Friday to talk about their book, which dives into the president's second term and is the result of more than 1,000 interviews. 

"This administration is so unrecognizable [compared] to Trump's first one," Haberman told "CBS Mornings" co-host Gayle King. 

She said "it became really clear to us," over many months of reporting, "that we were covering not the transfer of power from a Democrat to a Republican or a Democrat to a Democrat. This is a fundamentally different conception of the U.S. presidency."

Here are some of the key takeaways from their reporting.

Trump is using executive power like never before 

Swan said the second Trump administration, and the book, are "really about the way he's using executive power." 

"We haven't seen anything like this in our lifetime in terms of the unilateral expression of executive power," Swan said, noting that it comes at a time when "it's pretty hard to think of a precedent for a U.S. president having the command that Trump has had over his own party in Congress." 

"There really isn't a precedent. I mean, he basically got them to do whatever he wanted, and Congress wasn't even consulted when he went to war with Iran."

Even former President George W. Bush, for all the criticism of the wars he led in Iraq and Afghanistan, got congressional authorization, Swan noted. 

"Trump is just acting," Swan said. "He is acting and the system is trying to catch up to him. That's really the way it's working."

Trump is fundamentally changing the U.S. approach to foreign policy 

Through his unilateral actions, Mr. Trump is also changing the United States' approach to foreign policy, from his acquisition of Venezuelan oil to his unabated aspirations of acquiring Greenland. 

"It is changing how countries around the world, leaders around the world, how people in the U.S. look at their president, and we're not used to covering regime change, as you say, here," Haberman said. "But that is what we were doing." 

Two things that matter to Trump: Loyalty and looking the part

The president's decisions in picking top officials for critical roles boil down to two things, Haberman and Swan said: Is that person fiercely loyal to him, and do they look the part?

"Loyalty was a premier characteristic he was seeking, and loyalty — and we write about this — has a bit of a fungible definition," Haberman said. "What became the real litmus test was January 6th. Where you were on January 6th and where you were on January 7th? If on January 7th in Trump's mind in any way you were separated from him, he did not want you around."

The authors also wrote about how the president selected members of his Cabinet. According to the book, before picking John Ratcliffe as CIA director, the president said he thought he looked like actor Cary Grant, straight out of central casting.

"The 'central casting' aspect is a big one," Haberman said. "Part of that is Pete Hegseth, how you now have him as the secretary of defense/war. He liked that Hegseth was good on TV. He liked that Hegseth defended, quote unquote, warriors. When it comes to someone like Tulsi Gabbard, who was the director of national intelligence, it was, 'Let's give it to her, what harm could she really do?'"

Trump operates in an "information bubble" and is rarely told bad news 

Much more so than in his first term, the president operates in an "information bubble" where his advisers rarely tell him bad news, Haberman and Swan write. In the president's first term, he had more advisers who would push back on occasion — but not so much these days. 

Haberman noted that former President Joe Biden also hated receiving negative news, but she said, "Trump is in an information bubble that is unlike anything that I can remember."

"The inputs that are reaching him are so small," she said, adding that many times "decisions are being made by a group of about a half a dozen people."

For example, Haberman said, in the lead-up to the Iran war, "The energy secretary and the treasury secretary, the two people would have to manage the after-effects and economic impacts of a global energy crisis caused by this war, were not part of these meetings initially because they were concerned about leaks."

The Situation Room was used for meetings about Epstein files 

In a series of closely held meetings, the Situation Room — normally the site of top-level national security decisions — was used for discussions about how to handle fallout from Jeffrey Epstein and the Epstein files, Haberman and Swan write in their book. 

"This was a pretty extraordinary series of meetings that happened last summer and the setting itself was extraordinary," Swan said.

"Over the summer of last year they essentially turned the Situation Room into an Epstein crisis response center, and you had the most senior officials in the U.S. government gathering in that room to figure out essentially a PR strategy to deal with the Epstein crisis," he said.

"One of the problems they had was they built this website that they were going to release — a Justice Department public-facing website. And they were searching around in it for Trump and they were finding a lot of stuff on Trump and some of it was, you know, embarrassing, so they had to make decisions about what to disclose and what not to disclose. But that really was a political crisis that has had long-term effects way beyond what his team expected."