NASHUA, N.H.— Donald Trump made his decision to start skewering Sen. Ted Cruz as his private jet was approaching here earlier this month.
“Ted is hanging around the top too long,” the Republican presidential front-runner announced on the plane, according to his campaign manager. “Time to take him down.”
Mr. Trump’s airborne verdict to strike at his closest GOP rival and a look at other decisions like it reveal a truth behind his famously pointed attacks: Mr. Trump, not his staff or consultants, personally drives them, and they are both calculated and improvised to adapt to news and polls, with little research or extensive prep work.
Mr. Trump proceeded to question whether Mr. Cruz’s Canadian birth disqualified him. A week later, he tore into the Texas senator about a loan he took from Goldman Sachs to finance his political career and about his notoriety as a Senate “nasty guy.” The onslaught seemed to stall Mr. Cruz’s rise in Iowa, where polls show Mr. Trump holding an advantage.
In a repeated pattern, Mr. Trump has fired personal attacks at rivals when they emerge as a challenge. While his attacks and policy pronouncements often appear to be off-the-cuff, hours spent interviewing Mr. Trump and watching him behind the scenes show how he plots them, most often alone in his jet as he flies to early primary states.
“We do have a very big staff,” Mr. Trump said in an interview backstage just before an Ames, Iowa, appearance, “but I do like to make up my own mind on what I want to say.”
Mr. Trump flies the campaign trail with just a few senior aides. On a Jan. 18 flight to Concord, N.H., sitting in his cream-colored leather club chair at a pearlwood desk trimmed in 24-carat gold, he read and watched news reports on the race, jotting notes on his perceptions of candidates’ flaws.
Ten minutes before landing, he grabbed paper, scrawling five points—15 words—on what to say before his next adoring crowd. “I’m strategic, but trying to do the right thing and only saying what I have a very strong opinion on before going into battle,” he said on the plane. “Interestingly, people say that’s what everybody’s thinking but nobody wants to say it.”
His jotted items: “SELF-FUNDING SUPER PACS,” “NOW BLOCK SYRIAN REFUGEES,” “2ND AMENDMENT,” “HILLARY CLINTON A DISASTER,” “STOCK MARKET.”
At the event, he loosely followed his note, talking broadly and then returning to items on his list. After expressing support of the Second Amendment, he pointed out a few big men in the audience. “If we had you, and you, and you, with weapons, think how different the result would have been in Paris and San Bernardino.”
A key to his unscripted approach is his conversational style of speaking extemporaneously, incorporating the day’s news and gauging the crowd’s reaction. “Without a photographic memory, you can’t speak without notes,” Mr. Trump said. “My memory is one of the greats.”
Mr. Trump has shown a flair for touching the popular zeitgeist, such as in his position on immigration. But his campaign-by-counterpunch approach has critics charging him with eroding civility and raising the question of whether he has any positive message.
He drew new criticism for his weekend assertion in Iowa that he could “stand in the middle of Fifth Avenue and shoot somebody, and I wouldn’t lose voters.”
“Trump’s style degrades people and public discourse,” said Pete Wehner, a former White House adviser and speechwriter for President George W. Bush. “His keen sense to go for the jugular and play to the Kardashian culture is effective, but dangerous for failing to offer a positive vision for the country.”
“I’m doing it from the heart—and the brain,” Mr. Trump said. “A lot of it resonates.”
He has attacked former Florida Gov. Jeb Bush as “low energy,” Ben Carson by mocking the retired neurosurgeon’s story that a belt buckle spared a person he tried to stab as a teenager and Florida Sen. Marco Rubio for his “profuse sweating.”
Mr. Bush and Mr. Cruz have responded to his taunts by questioning his conservative credentials. Mr. Rubio and Mr. Carson repeatedly resisted opportunities to respond directly to his remarks.
In late December, Mr. Trump took on Democratic front-runner Hillary Clinton after she said he had “demonstrated a penchant for sexism.”
“If Hillary thinks she can unleash her husband, with his terrible record of women abuse, while playing the women’s card on me, she’s wrong!” he tweeted.
Last week, Mr. Trump alternated attacks between Mr. Cruz and Mrs. Clinton. At Liberty University in Lynchburg, Va., Mr. Trump held his fire against Mr. Cruz, who is popular with the evangelical audience. “I didn’t want to be hitting anybody” at the Christian school, Mr. Trump said afterward.
He uncharacteristically used one scripted line, citing a Bible verse from “two Corinthians” instead of “Second Corinthians,” drawing some chuckles from the audience. Back on his plane, an angry Mr. Trump reviewed his page of notes and saw he copied “2 Corinthians” exactly as emailed from Tony Perkins, president of the Family Research Council, who suggested its usage in the Liberty speech.
With social and cable media highlighting his gaffe, Mr. Trump blamed it on a momentary lapse of listening to someone other than himself. “I’m self-funding my campaign; no one can tell me what to say or do,” Mr. Trump said. “I do better that way.”
Mr. Perkins said: “I gave him the reference as you would find it in any English Bible.”
Mr. Trump, under fire for what some regard as his attacks on women, also is deploying his older daughter, Ivanka. Last week, the 34-year-old Trump Organization senior executive appeared with him at two events. “Stay near me so I point you out,” he told Ms. Trump, who is eight months pregnant with her third child, backstage.
On Mr. Trump’s jet next morning, a senior aide brought an Esquire magazine with the cover of Mr. Trump and the headline: “Hater in Chief.” At the rally that evening when Sarah Palin endorsed him, a few protesters yelled: “A vote for Trump is a vote for hate.” The crowd drowned them out: “U.S.A.! U.S.A.! U.S.A!.”
In his motorcade in Des Moines, Iowa, Mr. Trump said he wasn’t deterred by charges he is running a negative campaign. “A lot of times I sound negative, but ultimately I’m positive,” he said. “ ‘Make America Great Again’ is a very positive campaign.”
If his campaign doesn’t succeed, “the worst thing that happens, I’ll be standing in the middle of Turnberry with waves hitting me in the face,” Mr. Trump said, referring to a Trump golf resort on Scotland’s coast. “I’m either going to do it right, or I’m not going to do it at all.”
