(CNN) As members of the House Freedom Caucus plotted to seize control of Donald Trump's health care bill earlier this month, they discovered a key weakness in the President's strategy.

In a memo circulated to members of the conservative group, a top adviser to Sen. Rand Paul of Kentucky pointed out that Trump had made an uncharacteristic error: The President had violated his own rules in "The Art of the Deal."

Quoting from a passage of the book in which Trump urged readers never to seem too eager to cut a deal, the memo concluded Republican leaders appeared to have done just that. "The Speaker needs a deal right now, more than the Freedom Caucus. So does the White House."

Recognizing the immense leverage they enjoyed, members of the Freedom Caucus and other conservatives like Paul would stubbornly maintain their opposition to the House GOP bill to repeal and replace Obamacare. The lawmakers continued to press for concessions from Trump and House Speaker Paul Ryan, creating an impasse in negotiations that helped lead to the legislation's dramatic defeat on Friday.

And they were not alone in looking to "The Art of the Deal" for guidance.

Republican lawmakers on Capitol Hill have been desperately trying to understand Trump's psyche since he upended any semblance of political normalcy in Washington since his surprise election in November. Disoriented and bewildered by the former real estate mogul's unpredictable -- and at times seemingly erratic -- actions, Trump's colleagues in Congress have been consulting the president's own playbook.

On a Delta flight back to Washington last weekend, New York Rep. Peter King had a hardback copy of the "Art of the Deal," along with a folded up copy of that day's New York Times, tucked into the backseat pocket in front of him.

Veteran GOP Rep. Tom Cole of Oklahoma, who said he was blindsided by Trump's election, said he ordered a copy of the book soon after Election Day to educate himself about a man whose political appeal Cole had clearly underestimated.

"You get a new president and you want to learn as much about him as you can," Cole told CNN on Capitol Hill last week in the middle of the health care debate. "I think I'm getting an up close and personal look at the art of the deal right now and it's pretty impressive."

King said he started reading the book several weeks ago to prepare himself for legislative negotiations with the President. The Long Island congressman cited an old expression encouraging one to read an adversary's book.

"Not that he's my enemy, but I'm just saying -- you get into somebody's brain," King said. "If I'm trying to get him on my side on something, (I'll say): 'Hey, as you told so and so back in 1983...'"

He mused: "Seeing him as president and reading the book, it sort of makes a lot more sense."

Published in 1987 and written by Trump and ghostwriter Tony Schwartz , the nearly 400-page book chronicles the various business deals Trump struck over the years as he built a vast real estate empire.

The biography was a bestseller when it was first published, and some members of Congress say they read it years ago. GOP Rep. Leonard Lance of New Jersey, who came out against the health care bill last week despite facing pressure from the White House and GOP leaders, said he read "The Art of the Deal" around the time that he was minority leader of the New Jersey State Senate.

"I had to be involved in issues related to the gaming industry in New Jersey," Lance said. "I think (Trump) was an interesting personality long before his elevation to the presidency."

One week before the House was set to vote on GOP leadership's health care bill, Paul -- a vocal opponent of the proposal -- brought copies of "The Art of the Deal" for his House colleagues in the Freedom Caucus.

In an evening meeting at the Rayburn office building, Paul walked through the position that members of the Freedom Caucus found themselves in. Behind the senator was a placard that read: "USE YOUR LEVERAGE."

"The worst thing you can possibly do in a deal is seem desperate to make it. That makes the other guy smell blood, and then you're dead," the sign said, citing a passage from "The Art of the Deal."

A memo titled "Lessons from 'The Art of the Deal,'" which according to a source was drafted by Paul's top aide Doug Stafford, was also circulated to the conservative lawmakers in the room.

The first bullet urged the Freedom Caucus to "think big." "If you're gonna be thinking anyway, you might as well make it big," the memo quoted from Trump's memoir, and went on to caution lawmakers against settling for "tweaks to a bad bill."

"We came here to repeal Obamacare. Obamacare Lite doesn't do it, and small fixes are not enough."

Members of the Freedom Caucus appeared to heed this advice in subsequent days.

Even under intense pressure from GOP leaderships and Trump himself, the group remained opposed to the bill and insisted on further and drastic changes to the legislation. The Freedom Caucus wished to get to a "yes," its chairman, Mark Meadows, repeatedly said, but the bill simply did not go far enough in gutting Obamacare.

GOP Rep. Andy Harris, a Freedom Caucus member from Maryland, told CNN on Friday hours before Ryan conceded that the bill didn't have the votes to pass that he believed negotiations with Trump were not over.

The day before, Trump had dispatched his senior officials to Capitol Hill to inform GOP lawmakers that he was done debating the bill and that the House must vote on the legislation the next day.

But some members were inclined to see even Trump's ultimatum as yet another familiar trick from his book. Someone threatening to walk away, they reasoned, doesn't mean that they really will.

"Just because Mr. Trump has said, 'Look, I'm going to turn my attention away from this,' does not mean ... that he's not going to be involved in any way," Harris insisted to a group of reporters. "Nor does that mean that it's the final offer on anyone's part."

Harris continued: "These are all techniques in a negotiation."