CNN  — 

The one ironclad rule of friendship with Donald Trump is this: Eventually, he will turn on you.

That time came on Thursday for South Carolina Sen. Lindsey Graham, who has sacrificed much over the past four years to ingratiate himself with Trump, in the wake of the release of “Peril,” a book on Trump’s final year in office.

The book by authors Bob Woodward and Robert Costa documents Graham’s repeated – and unsuccessful – attempts to convince Trump to concede the 2020 election.

Trump, naturally, responded by savaging Graham, as well as fellow Republican Sen. Mike Lee of Utah.

“I spent virtually no time with Senators Mike Lee of Utah, or Lindsey Graham of South Carolina, talking about the 2020 Presidential Election Scam or, as it is viewed by many, the ‘Crime of the Century,’” Trump wrote in a statement sent via his Save America PAC. “Lindsey and Mike should be ashamed of themselves for not putting up the fight necessary to win.”

Trump’s heel-turn on Graham should surprise no one – least of all Graham himself. After all, the South Carolina senator had a prime view over the last few years of how nothing and no one is ever good enough for Trump. Everyone, eventually, lets him down. He is the only one truly dedicated to fighting the, uh, good fight.

Friendship with Trump is very much like being the manager or coach of a professional sports team. You take the job knowing that, at some indefinite time in the future, you will be fired from that job. And that the firing may not be entirely your fault! You may just wind up being the fall guy for a new regime or the victim of people (or your players) just getting bored.

That’s friendship to Trump. It’s purely transactional. He will be “friends” with you for as long as you are useful to him. If he tires of you or decides you have violated some unwritten rule about loyalty, he will turn on you. Every. Damn. Time.

The Point: Loyalty is a one-way street for Trump. Always has been. Always will be.