"Why," Trump asked in a tweet, "is A.G. Jeff Sessions asking the Inspector General to investigate potentially massive FISA abuse"? He then rags on the IG, dismissing his power, suggesting (incorrectly) he's "an Obama guy," before throwing his hands up and declaring the whole thing, "DISGRACEFUL!"

The very public rebuke was less a shock -- Trump routinely jabs Sessions -- as a surprise, considering what White House press secretary Sarah Sanders said, less than 24 hours earlier, about the attorney general's move.

"I haven't spoken with (Trump) to determine his feelings (about the IG investigation), but ... it's something that he has clearly had frustration over, so I would imagine he certainly supports the decision to look into what we feel to be some wrongdoing," Sanders told reporters.

Not quite.

Trump's relationship with Sessions has been, to borrow a term from the President, "beleaguered" for some time now, dating back to Sessions' decision in March 2017 to recuse himself from any probe related to the 2016 campaign. Since then, Trump has engaged in a kind of running critical meta-commentary on Sessions' conduct in office.

Whether Sessions survives this latest round of opprobrium is anyone's guess. He's done it before. What's more remarkable, for now at least, is how we got here. Sessions was the first sitting US senator to endorse Trump in 2016 and emerged as a trusted aide and surrogate on the trail.

Things have, to put it mildly, changed over the past year.

The Bannon connection

As unlikely as their alliance might appear on its face, the New York real estate mogul and prosecutor-turned-senator from Dixie had one thing very much in common: Steve Bannon.

Before coming aboard Trump's campaign as its CEO in the summer of 2016, Bannon ran Breitbart News, where there he developed a rapport with Sessions, a recurring guest on his radio show. Two days before Sessions formally endorsed Trump, he was on the air with Bannon , talking up a "movement" that sounded a whole lot like how Bannon viewed Trump's candidacy.

"I told Donald Trump this isn't a campaign, this is a movement," he said at a Madison, Alabama, rally ahead of the Super Tuesday primaries. "Look at what's happening. The American people are not happy with their government."

JUST WATCHED Sen. Jeff Sessions endorses Donald Trump Replay More Videos ... MUST WATCH Sen. Jeff Sessions endorses Donald Trump 01:28

It wasn't the first time Sessions donned Trump's "Make America Great Again" campaign hat in an Alabama football stadium. About six months earlier, he appeared onstage at another Trump event, in Mobile, making him -- for a time -- the highest-profile American politician willing to -- if not yet endorse Trump -- then sign on with his message.

"Thank you for the work you've put into the immigration issue," Sessions said. "I'm really impressed with your plan. And I know it will make a difference, and this crowd shows a lot of people agree with that."

On the trail and into the White House

A month before Sessions himself joined the ride, an aide in his Senate office, Stephen Miller, left Capitol Hill to become a senior policy adviser to the Trump campaign. Miller would go on to write Trump's acceptance speech at the Republican convention in Cleveland, along with a number of other highly touted -- and often controversial -- speeches. He works now as a White House adviser, with a strong influence on immigration policy, and speechwriter.

His boss wasn't far behind, and days after the endorsement and Super Tuesday romp , on March 3, 2016, Trump announced Sessions would lead his campaign's national security advisory committee.

Senator Sessions will serve as the

Chairman of my National Security

Advisory Committee. https://t.co/jQed1P6SD9 pic.twitter.com/n83Cbs4jtA — Donald J. Trump (@realDonaldTrump) March 4, 2016

"Mr. Trump and the American people know our country needs a clear-eyed foreign policy rooted in the national interest," Sessions said in statement posted by Trump on Facebook . "We need to understand the limits of our ability to intervene successfully in other nations. It is time for a healthy dose of foreign policy realism."

That meant "forming partnerships based on shared interests" in the Middle East, he added, advocating for the "safe return of migrants to their home countries" as part of a broader strategy to "protect our own national security."

Trump ran roughshod over the GOP primary field and on July 19, 2016, Sessions was given the ceremonial honor of formally entering his name into nomination at the RNC.

JUST WATCHED Donald Trump officially nominated for president Replay More Videos ... MUST WATCH Donald Trump officially nominated for president 01:03

"He loves his country and he is determined to see it be a winner again," Sessions said. "Donald Trump is the singular leader that can get this country back on track. He has the strength, the courage, the will to get it done."

Exactly one year later, The New York Times would publish a long interview from Trump's White House in which the President lamented nominating Sessions to his post at the Justice Department. Trump was -- and remains -- angry over Sessions' recusal, which came about in part because of the controversy surrounding his contacts with Sergey Kislyak, the recently departed Russian ambassador to the US.

The first of those meetings came on the sidelines in Cleveland, and another at Sessions' Senate office. Neither were disclosed at his confirmation hearings, leading Sessions to take the steps now believed to have poisoned his relationship with Trump.

The long goodbye?

Back in October 2016, when the Access Hollywood tape first became public, throwing Trump's candidacy into doubt, as Republican officials either went missing or called on him to leave the race, Sessions never flinched.

"This thing is overblown," he told Fox News , as video of Trump making lewd and sexually aggressive remarks in private flooded the airwaves before the second presidential debate. "Everybody knows that Trump likes women." Sessions then pivoted, indignantly, to what he suggested was the "overlooked ... power of the WikiLeaks on Hillary Clinton."

JUST WATCHED Sessions asked about 'Access Hollywood' tape Replay More Videos ... MUST WATCH Sessions asked about 'Access Hollywood' tape 01:26

But for all his loyalty, personally and politically, Sessions has been affixed to the hot seat now for months. Trump draws a direct line -- with no apparent detour to account for his firing of FBI director James Comey -- from the recusal to the appointment , by Deputy Attorney General Rod Rosenstein, of special counsel Robert Mueller.

"Sessions should have never recused himself, and if he was going to recuse himself, he should have told me before he took the job, and I would have picked somebody else," Trump told The New York Times during a bombshell interview published last July.

He continued: "So Jeff Sessions takes the job, gets into the job, recuses himself. I then have -- which, frankly, I think is very unfair to the President. How do you take a job and then recuse yourself? If he would have recused himself before the job, I would have said, 'Thanks, Jeff, but I can't, you know, I'm not going to take you.'"

By that weekend, Trump's simmering frustrations with the Russia investigations and fellow Republicans popped up to a boil. On Saturday, he launched a tweetstorm musing on his "complete power to pardon" and jabbing at "the A.G. or Special Council" (that's Sessions and Mueller) for not "looking at the many Hillary Clinton or Comey crimes."

Fast forward to another angsty Monday, this one with son-in-law and adviser Jared Kushner's meeting with Senate intelligence committee staffers leading many morning newscasts. From the White House, Trump reprised his rant -- this time with a little extra mustard.

"So why aren't the Committees and investigators, and of course our beleaguered A.G., looking into Crooked Hillarys crimes & Russia relations?" he tweeted, a question that never asked for an answer. Before noon, Axios would cite "West Wing confidants" in a report floating former New York City Mayor Rudy Giuliani -- who subsequently backed Sessions' recusal decision and denied the story -- as a possible replacement for Sessions.

The ax never fell, but its shadow still hangs over the attorney general, who seems outwardly content advancing his own agenda while brushing off Trump's attacks.

There are, surely, new roadblocks up ahead. The Mueller investigation continues apace and, should Trump eventually seek to end it, firing Sessions might become a necessity. If that's how it ends, the denouement will feel as inevitable as his union with Trump once seemed improbable.