Stephen K. Bannon, the architect of Donald Trump’s campaign and presidency, is a man with a lot of ideas. He believes that Western civilization is locked in an existential battle with the barbarians at the gates, that nationalists must wrest control from the aloof and corrupt globalist elite, and that America is a once great nation shackled by welfare for both the poor and the wealthy. It was a version of this narrative, market-tested on Breitbart News, that carried Mr. Trump to the presidency. One way to understand Trumpism is as applied Bannonism. The first few months of President Trump’s term have been an attempt to put all of that theory into practice, and by any reasonable standard, that attempt has failed.

As it turns out, there’s a difference between spinning yarns and the careful needlework of piecing together policy and political coalitions.

The travel ban was Mr. Bannon’s first high-profile defeat. The hastily written and sloppily executed executive order, intended to halt immigration and travel from seven Middle Eastern countries, was immediately met by widespread protests. Mr. Bannon attempted to spin this as a feature, not a bug, an attempt to provoke opposition from the right set of enemies, but even nominal allies recoiled from the ban’s capriciousness. Worse, the executive order was quickly halted by the courts, and even a revised version has not yet been able to pass muster with the judiciary.

Mr. Bannon’s most recent defeat is his removal from the National Security Council. As with the travel ban, he and his allies attempted to cast this as part of the plan. In his telling, he had taken a place on the council only to undo the work of Susan Rice, President Obama’s national security adviser; his allies said he was there to monitor Michael Flynn, the first national security adviser under President Trump. With those tasks accomplished, his work on the council was done. These explanations were quickly countered by leaks that portrayed Mr. Bannon as the loser of an internal power struggle, a depiction implicitly confirmed by leaks from his own camp.