(CNN) This time last year, Steve Bannon was on top of the world. He had shepherded Donald Trump to the most unlikely presidential victory ever. He was preparing to go with Trump to the White House as a senior strategist. He was the new hot thing.

Bannon is, suddenly, a man without a friend left in the world. So what's his next act? Or is he done?

To answer that I reached out to my friend Josh Green , who wrote the incredible Bannon biography " Devil's Bargain: Steve Bannon, Donald Trump, and the Storming of the Presidency ." Our email conversation about all things Bannon is below.

Cillizza: Josh, as the foremost Bannonologist in the country -- if that's not a thing, I am making it a thing right now -- I turn to you for wisdom at this amazing moment.

Steve Bannon appears to be totally and completely on the outs with Donald Trump, his political patron, after talking (at length) to Michael Wolff for "Fire and Fury." Trump said that Bannon lost his mind!

Trump appears to be WAY angrier at Bannon than when he actually fired him a few months back. So is this the end of the end? A seven-year political friendship turned into "Sloppy Steve"

Green: What Bannon did by talking to Wolff for this book -- and by extension, probably, talking to me for my book -- is pour a can of gasoline over his head and light a match. Trump appears to have broken with him in a way that seems final and ultimate, even tagging him with a dreaded nickname, "Sloppy Steve," which I think we can all admit is pretty fantastic.

Bannon has been in the doghouse before and come back. I hear that he thinks he can come back from this, too. We'll see; nothing's ever quite impossible in Trump's world. You can never say never.

As Bannon has told people in the past, Trump is entirely transactional. But if he loses his platform at Breitbart News, then it's hard for me to see how he'll be able to wield the kind of influence that I describe in "Devil's Bargain," and that he seemed to have regained after leaving the White House last year.

Cillizza: Let's talk about Bannon and Breitbart. There's reporting out there they may oust him. And Rebekah Mercer, one of the major financial patrons of Breitbart (and Bannon), said publicly that she and he are not on speaking terms and she's not going to be funding what he does anymore.

What's weird to me is that it appears Bannon's quotes on Trump to Wolff have had a far more profound effect on his role at Breitbart -- and in the conservative firmament more generally -- then when he was fired by Trump! After that, he was welcomed as a conquering hero back into Breitbart!

What the hell happened? Is it solely the Wolff book? The Roy Moore debacle?

And is Bannon really in danger of losing his Breitbart platform?

Green: The reason uber-wealthy people like the Mercers become involved in politics is to exert influence. Bannon was an agent of that influence, and the architect. And he did, for a time, have a profound influence on American politics that culminated in Trump's election. Bannon was the real force behind Breitbart; the head honcho at GAI, which produced the "Clinton Cash" book so damaging to Hillary's candidacy; and a board member at Cambridge Analytica : The reason uber-wealthy people like the Mercers become involved in politics is to exert influence. Bannon was an agent of that influence, and the architect. And he did, for a time, have a profound influence on American politics that culminated in Trump's election. Bannon was the real force behind Breitbart; the head honcho at GAI, which produced the "Clinton Cash" book so damaging to Hillary's candidacy; and a board member at Cambridge Analytica , the data research firm that worked on the Trump campaign

So as an investment, Bannon really did pay off for the Mercers like early-'80s Apple stock. The problem is that effectiveness waned almost immediately upon entering the White House, and that, coupled with his megalomania and his belief that he was the true leader of the nationalist movement, backfired on him big time.

Trump obviously doesn't value him the way that he did a year ago. With the humiliation of Moore's loss in Alabama and the devastating quotes in Wolff's book attacking Trump's family, there was really no reason to keep him around. And when Trump turns on someone, he really TURNS on them!

Cillizza: I am STUNNED that Bannon ever entertained the idea of a presidential bid. That would, um, never work.

But let's assume -- just for the purpose of the conversation -- he hangs on at Breitbart. How does he start to rebuild what he's lost? Can he?

And just for the thought experiment: If Breitbart jettisons Bannon -- where does he go then?

Green: Look, here on planet Earth we're all rightly astonished that Bannon holds (held?) presidential ambitions. But the psychology would work as follows: Bannon has always thought that Trump was riding a global nationalist wave that'd swept across Europe, the UK and now the US. Trump embraced that politics -- Bannon's politics -- and got elected. So clearly the ideas resonate in the US. If Trump were to decide against running for re-election, Bannon, believing he's the true carrier of the faith, must've thought, "Why not me?"

Like his ex-boss, he's always been a guy with a healthy ego. But if he were to lose the Breitbart platform, it's hard for me to envision what vehicle he would use to lead such a movement and how he would fund it. He's rich. But he's not self-fund-a-presidential-campaign rich.

Cillizza: OK. So a presidential bid is off. [Shakes hands, nods, walks away.]

BUT, what then does Bannon do? This guy is a news animal. He appears to be totally obsessed with the media, the battle of ideas between the two parties, all of it.

It feels impossible for someone like Steve Bannon to just disappear from, well, anywhere -- especially a world in which Donald Trump is president.

Green: In the near term, Bannon does (and is doing) what everybody who wants to influence and ingratiate themselves to Trump does: Flatter him with obsequious praise. It shouldn't be lost on anyone that after Bannon called Trump a "great man" on his radio show on the evening of his own defenestration, Trump quickly learned about it (probably from a cable TV chyron) and mentioned this to reporters at the White House pool spray on Thursday.

I'm skeptical it'll work. But that's the only path back for Bannon that I can imagine. Or, heck, why doesn't he run for president? It's an automatic way to get in front of the cameras and spread a message.