Despite a looming divide between President Donald Trump and Health and Human Services Secretary Robert F. Kennedy Jr. – at least when it comes to vaccine policy – the president has stood firm behind his top public health official, even amid growing scrutiny from GOP lawmakers.

The explanation for Trump’s loyalty to RFK Jr., argued Salon reporter Amanda Marcotte in an analysis published Wednesday, was a simple one.

“Being able to publicly call a bona fide Kennedy by their familial nickname is, for someone as narcissistic as Trump, a substance with heroin-levels of addictiveness,” Marcotte wrote.

“Sure, we can consult the checklists for narcissistic personality disorder – Trump seems to meet every one – but no diagnostic tools are necessary here. His belief that he can prove his superiority by aligning himself with those he views as high-status is evident every time he talks for more than two or three minutes.”

Trump has had well-documented interest – Marcotte argues it to be an “obsession” – with those he perceives as celebrities, so much so that he’s tapped many of them to serve in his administration.

He appointed Mehmet Oz, better known as “Dr. Oz, as the head of the Centers for Medicare and Medicaid Services; he picked former WWE executive Linda McMahon to head the Department of Education; and Howard Lutnick, a Wall Street executive who made an appearance on Trump’s show “The Apprentice,” was selected to lead the Commerce Department.

Many have attributed Trump’s loyalty to RFK Jr. as a political strategy, one that seeks to court independent voters, many of whom initially supported RFK Jr.’s failed presidential bid. For Trump, however, his support for RFK Jr. is no political strategy, Marcottee argued, but rather, one born out of “envy.”

“His obsession comes down to envy, which also appears on that narcissist checklist, and is one of Trump’s dominant personality traits, along with sadism, cowardice and racism,” she wrote. “...There’s no strategy here. Trump just likes being able to ring a Kennedy on the phone and call him ‘Bobby.’”