USA TODAY interview: Nikki Haley isn't running for president. That is, not yet.

NEW YORK – Nikki Haley wants to make it clear she’s not running for president.

In 2020.

But the former South Carolina governor and U.N. ambassador – author of "With All Due Respect," a new book about her experiences working for President Donald Trump – also leaves little question that she is positioning herself to be a contender to lead the GOP once Trump’s tenure is over.

So far, she has managed a high-wire act that has tripped up any number of fellow Republican officials: Maintain good relations with a disruptive president but also define some distance from him.

Take the now-infamous July 25 phone call between Trump and Ukrainian President Volodymyr Zelensky, now at the heart of a congressional impeachment inquiry. A White House summary of the conversation shows that Trump asked Zelensky to do a "favor" by investigating unsubstantiated allegations of corruption against former vice president Joe Biden and his son Hunter.

"I don't think it's good practice to ask a foreign country to investigate an American, period," Haley told USA TODAY. While her language is careful – no high dudgeon outrage here – it is a more plain-spoken rebuke of Trump than that offered by many GOP officeholders, with the notable exception of Utah Sen. Mitt Romney.

"It's a path you don't want to go down," she said.

She argues that impeachment is too drastic a penalty for the offense, though.

"I mean, did the president make the ask? Yes. Did Ukraine go through with the investigation? No. Did the president hold the money? No, he released it anyway," she said, referring to nearly $400 million in military aid that Congress had appropriated and the administration delayed.

Making the request was "not the best practice to do," she said, but added, "None of it panned out."

President Trump: Order Haley's book

Late Sunday, Trump welcomed her book on Twitter, encouraging his followers to "make sure you order your copy today" and adding, "Good luck Nikki!" Unlike many of her colleagues, she was able to leave the administration a year ago with a friendly Oval Office send-off rather than being fired with a derisive tweet.

But she also writes that she was "deeply disturbed" after the white supremacist march in Charlottesville, Virginia, in 2017 when Trump said there were "very fine people, on both sides." She called him then to express her concerns.

In the interview, she said the GOP should return to a focus on the federal deficit and the debt, which has ballooned during Trump's tenure, and communicate in ways that are less toxic and divisive than the current climate.

For Haley, the potential benefit of her I'm-with-Trump-but-not-always stance is that it could make her appealing or at least acceptable to both his most fervent backers and to more traditional Republicans who have viewed his tenure with alarm. The potential risk is that it could make her seem like weak tea to both, or worse.

Some critics blast her for trying to have it both ways. "Olympic apologist and unctuous opportunist in one quisling package," journalist Kara Swisher, co-founder of Recode, said in one tweet, then added another that called Haley a "hypocritical tattletale and exhausting classroom snitch."

'I can’t stop him': UN ambassador Haley used Trump's North Korea rhetoric as leverage

For the record, Haley said in the interview that during her tenure at the United Nations, she was never aware that Trump wanted Ukraine to investigate the Bidens or to pursue a debunked conspiracy theory that Ukraine, not Russia, was behind the hacking of Democratic Party computers during the 2016 campaign. That's another issue Trump raised with Zelensky.

She also didn't know that former New York Mayor Rudy Giuliani was running a sort of rogue foreign policy, she said. "I met with Rudy once, when I first got to the U.N., and we had a conversation just about cyber around the world, cyberattacks around the world."

Ukraine? No.

'I don't get confused'

The title of her new book, being published Tuesday by St. Martin's Press, is a reference to a signature push-back she made when White House economics adviser Larry Kudlow said at a news conference that she had suffered "some momentary confusion."

She had said on CBS' "Face the Nation" that the president was about to impose new sanctions on Russia, unaware that he had changed his mind the day before. Kudlow "threw me under the bus," Haley writes, bristling at his suggestion that she didn't have command of a key policy.

Haley sent an eight-word statement to Dana Perino of Fox News. "With all due respect," she told her, "I don't get confused."

Her weaponization of a pithy turn-of-phrase was reminiscent of an exchange she had with Trump on Twitter during the 2016 campaign. Haley, who had endorsed Florida Sen. Marco Rubio, demanded at a rally, "Donald Trump, show us your tax return!" Trump replied with a tweet, "The people of South Carolina are embarrassed by Nikki Haley!"

To which she responded, simply, "@realDonaldTrump, Bless your heart."

That was "southern-woman code," she writes. "Three polite words that let the receiver know you mean something not so polite."

The 262-page book is no tell-all. She disputes the characterization made by some former officials of Trump as uninformed and erratic, even dangerous. She makes a substantive case supporting his controversial decisions to withdraw from the Iran nuclear deal and the Paris climate accord. And she describes as appalling what seemed to be an effort by then-White House chief of staff John Kelly and then-Secretary of State Rex Tillerson to recruit her into the ranks of resistance.

Amid a heated internal debate over whether to cut off U.S. funding to a U.N. agency that served Palestinian refugees, the two men asked Haley to meet with them in Kelly's corner suite, down the hall from the Oval Office.

"Kelly and Tillerson confided in me that when they resisted the president, they weren't being insubordinate, they were trying to save the country," she writes. "It was their decisions, not the president's, that were in the best interests of America, they said. The president didn't know what he was doing."

She was shocked. "They were wrong in thinking that they were serving the country by trying to undermine the president," she said in the interview. "I just didn't want any part of it."

More: Nikki Haley says she rebuffed efforts by Tillerson, Kelly to thwart Trump

The conversation she recounts echoes an anonymous New York Times op-ed, published in September 2018 by someone identified only as a senior official in the Trump administration. "Many of the senior officials in his own administration are working diligently from within to frustrate parts of his agenda and his worst inclinations," it read. They were "thwarting Mr. Trump's more misguided impulses."

Doesn't Anonymous' column sound just like Kelly and Tillerson's comments to her?

"I would never, ever try and say that either of them were Anonymous," she said. "I mean, I don't get into gossip." She also called it "cowardly and arrogant" to level such a serious critique of the president but remain unnamed.

The anonymous author has written a book, "A Warning," being published next week. Early accounts report that it includes a tantalizing reference to Haley – that Trump was actively considering replacing Vice President Mike Pence with her. That has been the subject of persistent speculation.

"It's just not going to happen," Haley said. She called Pence "a great, loyal friend to the president" and a good vice president. "I think they're strong together, and I think they're going to win together."

In a USA TODAY/Suffolk University Poll last month, nearly one in five Republicans said they'd like someone else to jump into the 2020 race. The top name they suggested in response to an open-ended question was Haley – mentioned more often than Pence or Romney or former House Speaker Paul Ryan.

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Dealing with PTSD

Haley recounts in the book the 2015 slaughter of nine worshippers at the Emanuel African Methodist Episcopal Church in Charleston, a hate crime by an avowed white supremacist at the historic black church. In the aftermath, she negotiated with the state Legislature to remove from the State Capitol the Confederate flag, long a point of fierce debate.

Dealing with the mass shooting was devastating, she writes. The day after the murders, then-Connecticut governor Dan Malloy called to offer condolences and to caution her about the physical and emotional toll ahead for her. Malloy had been governor when 26 people, including 20 children, were massacred by a gunman at Sandy Hook Elementary School in 2012.

He turned out to be right. After spending her days trying to comfort the grieving and unite the state, Haley would find herself collapsing into tears at night. Unable to eat, she lost 20 pounds. She reveals in the book that her doctor warned her she was showing signs of post-traumatic stress disorder, and he arranged for her to begin seeing a therapist.

"It made me very conscious of the fragility of life and time and people, and it affected me greatly," she said in the interview. "I don't think I'll ever get rid of it. I don't think I'll know how to forget about it. And I don't know that I want to. I mean, it changed me."

She continues to have some symptoms of PTSD and she continues to see a therapist, she said. "I choose to do that because I think as long as you feel pain, you have to keep processing."

At age 47, Haley said she is glad to be "taking a breath" after 15 years of constantly running for and serving in office – six years in the South Carolina Legislature, six years as governor, two years at the United Nations.

Stepping down: Nikki Haley, top Trump aide, leaves post at UN

Her husband, Michael, serves in the South Carolina Army National Guard. Daughter Rena is a senior in college; son Nalin is a senior in high school. Her parents are now living with her in New York City. She has gone on the corporate board of Boeing.

But she has not left politics. She has launched Stand for America, a tax-exempt 501(c)4 advocacy group focused on conservative policy – the photo featured on the group's website shows her with Trump – and chairs a foundation she founded in South Carolina called The Original Six that supports after-school programs. She has been campaigning for Republican candidates from Colorado to Iowa.

Which, combined with the new book, sounds like the resume of a modern-day presidential hopeful.

As a woman and as the offspring of Indian immigrants, she would be a groundbreaking candidate. She was the first woman and first racial minority to be elected governor in South Carolina. The Republican Party has never nominated for president a woman or a person of color, demographic groups the GOP has struggled to hold.

Haley said it's too early to make a decision on running for the White House down the road, but she's not coy about the possibility. The word "ambitious" is too often wielded as a negative against women, she said. She acknowledges being ambitious, though she prefers the word "passionate," or maybe "badass." For now, she said, she's looking ahead one year at a time.

"You know, I always tried to do the best I could in every job I did," she said. "And when I did that, doors would open."

This article originally appeared on USA TODAY: Nikki Haley: Trump's ex UN ambassador isn't running for president yet