Jeff Sessions thought he was on the Trump team, but he was sadly mistaken.

For President Donald Trump, the world breaks down into three categories — there’s family, who are part of the charmed Trump circle by blood or marriage; there are “winners,” who have earned Trump’s regard by making lots of money (often at Goldman Sachs); and then there’s everyone else, who are adornments to be cast aside as Trump finds convenient.

Sessions is emphatically in the latter category. If the former Alabama senator wanted to be securely ensconced in Trump world, he should have had the foresight to marry Ivanka. Nothing else — not endorsing early, not carrying water in trying circumstances in the campaign — will ever make him anything more than some guy who happens to be attorney general of the United States.

Trump’s treatment of Sessions is unprecedented in the annals of American government. Cabinet officials have been hung out to dry before. They have been forced to resign or fired. Never before has a Cabinet secretary been publicly belittled in an ongoing campaign of humiliation by the president who appointed him.

The drama hangs a lantern on Trump’s flaws. Trump lacks gratitude, dismissing Sessions’ endorsement of him in the primaries as merely the senator’s reaction to the size of Trump’s crowds. He obviously doesn’t feel any respect for someone who, as an honorable person with a long career in public service, deserves it. He doesn’t care about propriety, which would dictate dressing down Sessions in private, not flaying him in public. And, finally, he doesn’t feel any obligation to Sessions, despite the fact that Sessions gave up a safe Senate seat to serve in his administration.

For Trump, loyalty is unilateral, not reciprocal, and it has a very particular content. It’s not loyalty to the agenda or to the party, but to Trump, specifically his personal interests and honor.

Robert Mueller’s investigation, at the very least, creates an ongoing cloud over Trump’s election victory. Insofar as the president believes that Sessions enabled this assault on his ego, the attorney general is persona non grata. He might as well have told the president that, yes, Barack Obama had a bigger inaugural crowd.

As a result, Trump is demeaning his attorney general and using the same weapons he uses against any of his targets — namely, anything at hand.

Trump hits Sessions for not pursuing Hillary Clinton, when the president himself had called for letting the Clinton scandal go. He criticizes Sessions for not firing FBI official Andrew McCabe, even though the White House reportedly interviewed McCabe to replace James Comey permanently as FBI director. Sessions should consider himself lucky that Trump has not, as of yet, accused any of his family members of being involved in the assassination of John F. Kennedy.

Of course, Trump is free to fire Sessions whenever he likes. That he is not doing it and prefers to run him down, apparently in hopes that he will quit, speaks to an unwillingness to take responsibility. This is his government; he should either back his appointees or cashier them, not troll them on Twitter.

The episode shows the challenge that Republicans face in Trump. It is not ideological. Substantively, Trump is governing as more or less a conventional Republican. The challenge is characterological. How to work with a president who is key to advancing much of the GOP agenda without endorsing his brazen disregard for institutional and personal norms?

The Sessions imbroglio may blow over, as Trump moves on to the next thing. But it offers a window into how Trump could collapse his own administration — by letting the pressure of criticism and investigation get the best of him, destroying any cohesiveness within his own government and party, and creating an ongoing sense of crisis that eventually spirals out of control.

If this nightmare scenario becomes reality, the bizarre campaign against Jeff Sessions will have been a sign of things to come.

Rich Lowry is a syndicated columnist. He can be reached via e-mail at: comments.lowry@nationalreview.com.