If there is one thing to keep in mind about what makes President Donald Trump tick, it is this: Ultimately everything is always about Donald Trump and his core family. This simple, but essential rule helps shed light on what to make of Steve Bannon's nasty public banishment from Trump's circle of friends, advisors and donors.

Applying this rule helps explain the split between Trump and Bannon. What hurt Bannon more than anything else were probably his vicious comments about Trump himself, and his children Ivanka and Donald Jr., not his political musings or the fact that he spilled the beans about the inner workings of the White House to the author of a brutal take-down book.

But applying this rule that when push comes to shove Trump ultimately only cares about himself and his family also helps explain why Bannon's demise does not mean the end of Trumpism. Because Trumpism, to the extent it exists, was never about Steve Bannon, nationalism, isolationism, or for that matter about anything resembling something close to a coherent ideology or a mature worldview.

Core of Trumpism

Trumpism, understood correctly, at its core, could always be summed up as Donald Trump first. This, by the way, was true long before Trump became president or even before his candidacy. According to his biographers it has been always been this way. And that's why Trumpism will remain with us even after Steve Bannon is gone, just as it did after the exit of previous highly praised people in Trump's orbit such as former National Security Advisor Michael Flynn, former White House spokesman Anthony Scaramucci and numerous others.

Having said that, it is of course true that Steve Bannon was arguably more influential in shaping the president's broader political agenda and views than most other non-family members. But it is also true, as President Trump has said, that Bannon only became his presidential campaign manager after Trump had already defeated a large field of Republican candidates and clinched the party's nomination.

Trump's nefarious anti-immigration remarks in declaring his intention to run for president back in 2015, in which he accused Mexico of sending "rapists" to the US and vowed to build a "great, great wall" along the southern US border, were made without Bannon's involvement. But while the now former head of right-wing website Breitbart News had no official role in the campaign at the time, he and Trump reportedly knew, liked and talked to each other even before latter's candidacy. It is therefore likely that his ideas already resonated with Trump back then.

Odd couple

In a way, and for a time, the couple were a perfect match. Bannon, a former Goldman Sachs banker turned economic nationalist who boasted about making Breitbart into a platform for the alt-right and was yearning for a revolution in Washington, met Trump, a real estate mogul with the biggest aspirations for himself, but devoid of any sort of coherent political worldview beyond a vague winner-take-all mentality.

Trump, ready to say just about anything to win, became the perfect vehicle to advance Bannon's crude ideological views to the highest office in the country. And Trump was eager and happy to have someone who supplied him with ideas that, most importantly, grabbed the public's attention and kept him in the limelight on his way to an unexpected election victory.

But since Trump's surprising election victory Bannon's star was already beginning to shine too brightly for a president who craves the limelight . A Time Magazine cover featuring Bannon and the headline "the great manipulator" shortly after the inauguration reportedly irked Trump, who is rumored to keep track of how often he appears on the front of the publication.

GOP and Trump 

Things went slowly downhill from there for Bannon and seemingly culminated in his exit from the White House last summer. Back then, Trump still had friendly words to say about Bannon. Now, though, the president has blasted Bannon in a strongly worded press release and via Twitter. Rebekah Mercer, whose right-wing billionaire father was a major donor to the Trump campaign and had financed Breitbart, subsequently announced her family was cutting ties with Bannon.

Predictably, many establishment Republicans in Congress and elsewhere who had fought Bannon tooth and nail all along celebrated Trump's public break with their nemesis, hoping to increase their sway over Trump now that Bannon is gone.

But they should not get their hopes up too high. Because as evidenced during the presidential campaign and since when he openly lambasted the party and its leaders, Trump is not beholden to the Republican establishment. Trump will work with the GOP when he believes it suits him personally and he won't when he believes it does not. That's because the core of Trumpism remains unchanged whether Steve Bannon is gone or not: Donald Trump first.