On Monday morning, President Donald Trump decided that there was an urgent matter he needed to clear up for the public. “I call my own shots, largely based on an accumulation of data, and everyone knows it,” he tweeted. “Some FAKE NEWS media, in order to marginalize, lies!”

It may seem odd that the president of the United States would feel compelled to remind the country that he is actually in charge. But over the past week and a half of Trump’s young presidency, a narrative has been gaining steam in the media and among political observers that it is not Trump but in fact White House chief strategist Steve Bannon who is actually running the show.

In the wake of the chaos following Trump’s order banning entry into the US from nationals of seven majority-Muslim countries — and in the wake of reports that Bannon was the chief architect of the policy — the hashtag #PresidentBannon began to spread on Twitter, and images of Bannon as a puppet master pulling Trump’s strings became commonplace. A Saturday Night Live skit concluded an Oval Office session with its version of Bannon asking Trump for the president’s desk back, and Alec Baldwin as Trump responding, “Yes, of course, Mr. President.”

Perhaps most prominently, Time magazine put Bannon on a striking cover and dubbed him “The Great Manipulator.” Just whom he might be manipulating was left unstated.

MSNBC host Joe Scarborough cited the Time cover in a Morning Joe segment Monday as an example of how “this Steve Bannon thing just keeps coming up, people are saying ‘President Steve Bannon.’” Scarborough added that it was very unusual for a White House staffer to develop such a high profile so quickly, and though he professed to believe that “Donald Trump is the final decider,” he said that other people keep wanting to hear about Bannon’s influence. (Trump’s “I call my own shots” tweet, which came less than an hour later, may have been a direct response to this exchange, and it also calls to mind President George W. Bush’s “I’m the decider” remark.)

For some, the “President Bannon” meme is useful as a deliberate attempt to annoy a president they view as thin-skinned and egotistical. But while it’s surely going too far to say that Bannon is “the real president” — he does work for Trump and serve at his pleasure, after all — the chief strategist has indeed been remarkably influential in shaping the new administration so far. Not only are his fingerprints all over the most controversial parts of Trump’s immigration actions, but that same weekend Trump announced another order that gave Bannon a full seat on the National Security Council Principals Committee, which is unprecedented for a White House political adviser.

Furthermore, while the “powerful political aide skilled in the dark, manipulative arts” is a common trope, Bannon isn’t just any aide. His prominence is particularly noteworthy because there are indications that he is more hard-line than Trump in certain ways. Where Trump has said he loves legal immigration, Bannon has called it a “problem.” Where Trump has often been cozy with moneyed elites on Wall Street and in Hollywood, Bannon professes to despise them. Bannon has even predicted that the US will go to war in the South China Sea within five to 10 years.

Many liberals, and even many conservatives, therefore find Bannon’s apparent influence on Trump immensely disturbing. And that’s just the way Bannon likes it.

1) Who is Steve Bannon?

Stephen K. Bannon grew up in Virginia, served in the Navy, went to Harvard Business School, became a banker at Goldman Sachs, and eventually got very, very rich from a deal in which he got a share of royalties from the TV show Seinfeld. His wealth freed him up to pursue his own interests, first as a documentary filmmaker and then as a close associate of Andrew Breitbart, the conservative political activist who founded the website Breitbart News. After Breitbart himself died suddenly in 2012, Bannon took over the site as executive chair.

Under Bannon, Breitbart News filled a unique role in the conservative media ecosystem. The site was relentlessly critical of Obama and top Democrats, but also of top Republicans it portrayed as sellouts to powerful interests, like House Speaker Paul Ryan and his predecessor John Boehner. The site’s tone and editorial choices on racial matters are also the subject of major controversy — the site spotlights tales of lurid crimes committed by unauthorized immigrants, Muslims, and African Americans, and Bannon himself has called the site “the platform for the alt-right,” according to Mother Jones.

So when Trump launched his presidential campaign, the anti-immigrant, anti-Muslim, anti-elite rhetoric he used all sounded familiar to Breitbart readers. Under Bannon, Breitbart News’s coverage became staunchly pro-Trump. Few then were surprised when, in an August 2016 shake-up, Trump brought on Bannon as his campaign CEO — this was merely the formalization of an alliance that had already existed for many months. When Trump unexpectedly won the election, he decided to reward Bannon with a top White House job. (Josh Green wrote the definitive pre–White House profile of Bannon, and Zack Beauchamp has a fuller explainer on the history of Bannon and Breitbart.)

2) Why would anyone get the idea that Bannon has a different agenda than Trump?

The idea that Steve Bannon might be manipulating Donald Trump to advance his own agenda doesn’t come out of nowhere — in fact, it comes from Bannon’s own lips. As late as summer 2016, when Bannon was still at Breitbart and just months before he moved to the Trump campaign, he told a journalist that Trump was a “blunt instrument for us” and said, “I don’t know whether he really gets it or not.”

Who is the “us” there? Overall, Bannon sees himself, Breitbart, and now Trump as allies in what he calls a “global populist movement,” which is taking back the interests of “the people” against various malefactors like rapacious capitalists, open borders “globalists,” unauthorized immigrants, and radical Islamists. He’s the type of person who pontificates a lot about how “the Judeo-Christian West” is under siege, and who thinks the US and many European governments are failing to appropriately defend the interests of people born there.

The word Bannon has embraced to describe this movement is “nationalism.” Indeed, he sees himself and Trump as embarking on a conscious project to demolish the old American political camps and “build an entirely new political movement," he told Michael Wolff in November. "I'm not a white nationalist, I'm a nationalist. I'm an economic nationalist," he continued. “It will be as exciting as the 1930s, greater than the Reagan revolution — conservatives, plus populists, in an economic nationalist movement."

According to the Daily Beast’s Ronald Radosh, Bannon gave an even more grandiose statement of his motivations a few years back. He called himself a “Leninist” because “Lenin wanted to destroy the state, and that’s my goal too. I want to bring everything crashing down, and destroy all of today’s establishment.” (Bannon now claims he doesn’t remember saying this.)

But despite Bannon’s denials, there are unmistakable racial and ethnic aspects to the movement he’s building, and critics argue “white nationalism” is in fact the key to his project. Bannon has often sought to drum up political support (in the form of either pageviews or votes) by mobilizing white Americans against various frightening “others” — whether they’re Black Lives Matter protesters, immigrants, or refugees.

Much of this fits quite well with Trump’s worldview. But Trump has also appointed many more traditional Republicans to his administration, and could conceivably be swayed toward more mainstream policies as a result. Bannon also seems to genuinely differ from Trump on a couple fronts. First, there’s sometimes a religious tinge to his rhetoric — he’s argued that “secularism has sapped the strength of the Judeo-Christian West to defend its ideals,” and has even taken an interest in internal Vatican disputes.

Second, while Trump says legal immigration is wonderful, Bannon views it as a “problem and thinks it needs to be cut back.” This was dramatically demonstrated in an exchange the two had on Bannon’s radio show in November 2015, in which Bannon made the false claim that most Silicon Valley CEOs were from Asia and expressed his unhappiness with that. “A country’s more than an economy. We’re a civic society,” he said.

Not just illegal immigrants but immigrants in general, Bannon seemed to believe, were sapping America’s Americanness. In this, he goes further than Trump, but he’s in alignment with several other important figures in the new administration. Most prominent among these are attorney general nominee Jeff Sessions and several former Sessions aides, including senior White House adviser Stephen Miller. Past public statements make clear that Bannon, Sessions, and Miller are all harsh critics of even legal immigration. In some tellings, they are frequently pitted against more traditional Republicans in administration disputes.

3) What is Bannon’s White House job?

It’s hardly unprecedented for a president to give a political adviser a top job, as George W. Bush did for Karl Rove and Barack Obama did for David Axelrod. But recent incoming presidents have tended to designate one chief of staff who is indisputably in charge.

Not Trump. In a November press release, the Trump transition announced that Republican National Committee Chair Reince Priebus would be chief of staff — but that Bannon would fill the newly created position of “chief strategist.” Priebus and Bannon, the press release said, would work as “equal partners.” And yet Kremlinologists couldn't help noticing that Bannon’s name was listed first.

Bannon, it should be noted, fits the stereotype of the sinister political adviser to a T —and even seems to revel in it. “Darkness is good,” he told Wolff. “Dick Cheney. Darth Vader. Satan. That's power.” Note that Bannon said this after the election and his appointment to a top White House job. (These comments are why Saturday Night Live portrayed him as the Grim Reaper in its recent skit.)

But as chief strategist, Bannon is more than just a political adviser. He’s taken on a major role in policy and is, by most accounts, the leading force in crafting the Trump administration’s agenda — especially the series of White House–issued executive orders with which Trump began his presidency. “Mr. Bannon has rushed into the vacuum, telling allies that he and Mr. Miller have a brief window in which to push through their vision of Mr. Trump’s economic nationalism,” the New York Times’s Glenn Thrush and Maggie Haberman report.

4) So where did “President Bannon” come from?

As the transition proceeded, many top White House positions and Cabinet jobs went to traditional Republicans rather than Bannon-esque outsiders, suggesting to some observers that the steady hand of Priebus was at the helm and that the Trump administration might actually end up being surprisingly normal.

That narrative exploded on January 27, Trump’s seventh full day in office. On that day, Trump issued the executive order meant to block all refugees, and nationals of seven majority-Muslim countries, from entering the US for several months.

Chaos ensued. Hundreds of people who had been previously cleared to enter the US were detained at airports around the country or prevented from boarding their flights to the US at all. Shockingly, the administration initially applied the entry ban to green card holders too, even though many of them had lived and worked in the US for years. Thousands turned out to protest, even many Republicans started to criticize the order, and a series of lawsuits soon brought the policy to a screeching halt.

The blame game that ensued during and after all this made clear the order was a Steve Bannon production. A set of reports described the order as crafted by Bannon and Miller with minimal input from the relevant agencies. One of its most objectionable features — the ban on entry for green card holders — was personally dictated by Bannon and Miller over the Department of Homeland Security’s objections, according to CNN’s Evan Perez and Pamela Brown.

Furthermore, it turned out that Bannon had a starring role in the other executive action Trump signed alongside the immigration order that Friday. This order gave Bannon a permanent seat on the Principals Committee of the National Security Council, placing him among the president’s top foreign policy advisers — an unprecedented role for a political hand.

Thrush and Haberman report that Trump was angry afterward because he “was not fully briefed” on that order’s details, and that it was an even “greater source of frustration to the president than the fallout from the travel ban.” (However, Time’s Zeke Miller has his own source saying that Trump was in fact briefed on Bannon’s new role.) In any case, the reports on Bannon’s role in the immigration order converged with this NSC order, and the “President Bannon” meme was born, making him a sort of combination Dick Cheney/Karl Rove figure in the minds of liberals.

5) What’s next for Bannon in the White House?

The fallout from the travel ban controversy has apparently led to Bannon being reined in somewhat. Both the Wall Street Journal and the Washington Post report Trump has clarified to his staff that Priebus is his top aide and that policy changes have to go through him and through a more rigorous vetting process.

By all accounts, though, Bannon remains very influential, and there’s no real talk of him being on the outs with Trump — not yet, at least. Indeed, Bannon and Trump have come a long way together. They share similar pugilistic instincts and a willingness to flout the political class’s conventional wisdom. Plus, it’s understandable if Trump places a great deal of stock in Bannon’s political instincts, since Bannon did oversee a campaign that put him in the White House despite the predictions of practically every expert.

But Bannon will only continue to keep that influence if Trump is satisfied with how his presidency is going. And while the strategy of constantly throwing red meat to the base worked well to boost Breitbart News’s traffic numbers and to win Trump the election, it has not worked so well when it comes to governance. All it has done so far is earned Trump record-low job approval for a new president.

So at some point, Trump may have to decide whether holding on to the loyalty of Bannon’s movement is really enough. Perhaps he might decide he’d prefer trying to convert some new voters to his side. And if he does opt for that route, Steve Bannon may no longer be so useful to him.