Steve Bannon just got Jeff Flaked.

The former Trump strategist who has been on a chest-thumping tour vowing to defeat any Republican officeholder insufficiently loyal to Donald Trump got savagely attacked by the president for his insufficient loyalty.

Nothing with Trump is final. Perhaps he’ll be talking to Bannon again soon enough. But Trump has dealt a severe blow to a man who has built a brand upon being the ultimate Trumpist, waging perpetual #war against the establishment for the good of his liege lord in the White House.

Bannon finds himself in the position of a parish priest who has been roundly denounced by the pope. Whose claim to represent the true faith is more likely to stand up?

This is the crux of the matter: Bannon thinks he created Trump, and Trump thinks he created Bannon. They had a fundamental disagreement about who was using whom, and in any such conflict, the president of the United States is going to win.

The Trump statement on Bannon is — of course — exaggerated and overly harsh. It nonetheless nails important things about the former White House official.

He was an inveterate leaker and poisonous infighter. Some of Bannon’s energy was devoted to trying to destroy Trump’s notably noncorrupt and nonkooky national security adviser, H.R. McMaster. Most of it, though, was directed at Trump’s children and son-in-law.

Both Bannon’s leaking and his war against the next generation of Trumps came together in Michael Wolff’s upcoming book, “Fire and Fury,” in which Bannon roasted Jared Kushner and Donald Trump Jr. for their alleged treasonous idiocy. It’s as if Reagan budget director David Stockman, in his notorious interview with The Atlantic in 1981, had slammed not only Ronald Reagan’s fiscal policy, but his kids as well.

Bannon also is a flagrant self-promoter. By any reasonable standard, it’s quite a comedown to go from working a few paces from the Oval Office to running a shoddy website devoid of true journalistic interest. With the help of a complicit and credulous media, Bannon made his cashiering from the White House seem like a glorious new chapter. He was going to be the leader of a movement vanquishing unworthy Republicans on behalf of Trump.

This effort stumbled badly out of the block with the Roy Moore debacle, and now the president has hampered it further. It’s not clear whether Bannon was raising real money — his extensive entourage notwithstanding — but his fundraising just got much harder. Part of Bannon’s appeal to candidates was bringing the imprimatur of Trump, and that, too, has been dented.

At the beginning of 2016, it seemed that Steve Bannon could be a figure like Karl Rove or David Axelrod, a political strategist with outsize influence over policy who existed at the very top of our national politics for years. Instead, he’s been kicked to the curb more brutally than any presidential aide in modern history.

This, obviously, has much to do with Trump himself, who is volatile, jealous of media attention and insistent that loyalty runs only one way, up to him. But Bannon played his hand badly. He had no idea how to effect his dream of a protectionist, isolationist administration spending massively on infrastructure and raising taxes on the rich. His vision lacked support within the administration and in Washington more broadly.

The past month has been telling. While Bannon contributed more than his share to the loss of a Republican Senate seat in Alabama in the name of the “Trump agenda,” his nemeses Paul Ryan and Mitch McConnell succeeded in passing a hugely consequential piece of the Trump agenda, the tax reform bill.

There will be much speculation about what the Trump-Bannon falling out means for Trump’s base. The answer is nothing. Trump’s base is Trump’s. No one ever voted for Steve Bannon, and now he is on the wrong side of the president in whose name he has presumed to speak.

Rich Lowry can be reached via e-mail: comments.lowry@nationalreview.com.