President Trump talks to then-chief White House strategist Stephen K. Bannon in January 2016. (Carlos Barria/Reuters)

If there was one member of Donald Trump's campaign and White House staff who most closely mirrored his own political tendencies and views, it was Stephen K. Bannon. From their uniquely pronounced nationalism to their distaste for establishment elites to their rough edges — Bannon affectionately labeled Trump the “honey badger” — it seemed like a match made in Breitbart heaven.

And then it imploded — about as quickly as it got off the ground — leaving Trump as president and Bannon as a shell of the political entity he once was. And for that, Bannon has his own honey-badger-esque chutzpah to blame.

On Tuesday, Bannon announced that he was stepping down from Breitbart. It marked the final blow during a week in which he lost President Trump as an ally, then his top financial backers in the Mercers and now his entire media platform. A man who recently set about to reshape the Republican Party after leaving the White House now has basically nothing from which to build such a campaign, thanks to wayward comments about Trump's family in Michael Wolff's new book.

What's particularly remarkable about Bannon's fall is how entirely Trumpian it was. From his perch in the White House, Bannon apparently felt invincible enough to spout off to Wolff about how that meeting Donald Trump Jr. had with a Russian lawyer was “treasonous” and about how Ivanka Trump was “dumb as a brick.” (Questions have been raised about some of the claims in Wolff's book, but Bannon hasn't disputed these quotes.) How he didn't realize that saying such things about Trump's family might cause a problem or two is the biggest mystery.

But it's also understandable in context, and it speaks to the prevailing chutzpah of the Trump White House. To Trump and those around him, his 2016 win has long served as vindication of their entire approach to politics. They could do no wrong because they won. The media that sought to criticize what Trump did and that said he wouldn't win was proved wrong, and Trump and Bannon were proving their superiority day in and day out.

But while that kind of ego might be sustainable in a chief executive, Bannon was always expendable to Trump. Republican after Republican has run afoul of Trump, and just about each and every time the GOP base turned on whoever wasn't on board with the president. For all Trump's political problems, the base is the one thing he's got on lock. So when Bannon alienated Trump and Trump bucked, the decision to pick a side wasn't hard for the Mercers or for Breitbart.

The Breitbart ethos is fueled by a sense of almost religious righteousness, and Bannon has that in spades. He took that to the Trump campaign, where Trump surely appreciated having a kindred spirit, and then to the White House. But Bannon clearly miscalculated his stature next to Trump and his ability to say just about anything, just like his boss.

And he has now paid dearly for it with one of the most spectacular falls from grace in U.S. politics.

Update: Adding insult to injury.