Inside Natalie Harp's Feud With Brother Preston — After He Branded His Sister's Trump Obsession 'Very Unhealthy'

Natalie Harp has reportedly been estranged from her older brother, Preston Harp, for more than six years.

The White House aide has faced increased scrutiny after letters written to President Donald Trump in 2023 resurfaced, in which she reportedly expressed her devotion to him. Her estranged brother has also described her infatuation with the commander-in-chief as "very unhealthy."

As the family drama unfolds, RadarOnline.com can take a closer look at Natalie and Preston's strained relationship.

Preston and Natalie grew up in a conservative Christian household in Southern California. They were homeschooled by their mother, Jill Harp, using Bible-based educational materials from Bob Jones University Press.

"We were raised with the idea that America was God's gift to the world and it's the only place that people really live in freedom," Preston told a publication in August.

The siblings were close growing up but gradually drifted apart as they developed different interests and political beliefs. Preston claimed Jill began monitoring their conversations as his political views became more progressive.

"I wasn't really allowed to be in her life," he said. "If we ever talked on the phone, my mom was listening to everything we'd say, and they were talking on the phone together with me on speakerphone."

Preston and Natalie's father, Robert Harp, a professor at Biola University, died by suicide on July 17, 2020, at the age of 61.

"Since my very first meeting with Bob, he has held a special place in my heart," Deborah Taylor, Biola's provost and senior vice president, said in a statement. "Bob always took the time to stop me on the sidewalk to share an uplifting story, accompanied by his big smile and joyful outlook on life."

The statement continued, "Periodically, he sent me notes of encouragement – either to share something exciting that happened for one of his students or simply to affirm my leadership and assure me of his prayers. I will deeply miss our impromptu conversations and his distinct way of radiating the joy of the Lord."

In an interview, Preston recalled receiving a call from Natalie about an emergency involving their father.

Upon arriving at the family home following Robert's death, Preston claimed Jill wanted him to tell others that Robert had died in his sleep. However, he refused to conceal the circumstances of his father's death, leading to a dispute that ignited a major family rift.

Preston said, "I just said, 'I'm going to say what the police said.' He hung himself in the garage."

"That was the last time I ever talked to my sister," he told a publication.

Natalie's increasing political involvement reportedly widened the divide between her and Preston.

In a June 2019 LinkedIn post, Natalie wrote she was a "Millennial woman fighting cancer" who was left "housebound and searching for care" after a nurse mixed up her IV "with a deadly substance of sterile water" in November 2015.

She then credited the president's "Right to Try" with saving her life.

"While some may argue that this legislation has not benefited the terminally ill or was repetitive to existing law, I beg to differ," she wrote, in part. "My oncologist didn't tell me I had other options. Donald Trump did. So I found another oncologist who was willing to try a different approach – an FDA-approved immunotherapy drug for an unapproved use. Now my numbers are stabilizing and so is my pain."

Her story also led to an appearance on Fox News, during which the POTUS called her an "incredible, unbelievable, young woman."

"She lit up the television screen like very few people I've ever seen do it," Preston said of Natalie's TV appearance.

One month after Robert's death, she spoke highly of Trump again in a speech at the 2020 Republican National Convention. She subsequently joined the Republican leader's communications team, and personal letters she allegedly sent Trump in 2023 later emerged.

In addition to describing Natalie's attachment to Trump as "very unhealthy," Preston suggested his sister's admiration for the president stemmed from their upbringing.

"The way my sister interacted with and treated my dad throughout the years, it was like she wished she had a different dad," he said in an interview.

Preston also dismissed Natalie's claim that Trump was her "first exposure to politics," telling anchor Erin Burnett his younger sibling had been fascinated by the presidency since her teenage years and had written letters to previous U.S. leaders.

Preston relocated to Masaya, Nicaragua, in 2023, where he has since embraced left-wing politics and become a supporter of the Sandinista movement.

During his CNN interview, he indicated he had no plans to return to the U.S. or reconcile with Jill or Natalie.

"I can't connect with that vibe, so I'm just going to leave it," Preston continued.