President Trump gave a contentious speech at a campaign rally in Phoenix on Aug. 22, attacking the media, GOP senators and "obstructionist" Democrats. Here are the highlights. (Jenny Starrs/The Washington Post)

Steve Bannon knows what he's doing.

After Breitbart News walloped President Trump for his Monday speech on Afghanistan that seemed to betray the noninterventionist vision of his campaign, Trump thrilled the website run by his former chief strategist by thrashing the media and vowing to “build that wall,” even if it means shutting down the government, during a Tuesday night rally in Phoenix.

At times, Trump sounded an awful lot like Bannon himself.

“I really think they don't like our country. I really believe that,” Trump said of journalists. “You would think they'd want to make our country great again, and I honestly believe they don't.”

This was not Trump's standard claim that news reports are “fake.” This was something sharper — an assertion that journalists are unpatriotic and actually want bad things to happen.

It was the same message that Bannon, in a rare public appearance, delivered at the Conservative Political Action Conference in February.

“As economic conditions get better, as more jobs get better, they're going to continue to fight,” Bannon said of the press, suggesting reporters don't want the economy to improve. “If you think they're going to give you your country back without a fight, you are sadly mistaken. Every day — every day — it is going to be a fight.”

As Trump channeled Bannon's language in Phoenix Breitbart's home page looked more like its usual self on Wednesday morning. (Notice the ad for the Bannon fidget spinner, billed as “a great distraction in between pulling down monuments.”)

Influence is difficult to quantify, and it would probably be an oversimplification to say that Trump's performance in Phoenix was a direct result of Breitbart's criticism of his address the night before. But we know that the president pays close attention to his press coverage, as evidenced by his Twitter account.

Bannon knows this about his former boss and seemed to believe from the time Trump was elected that outside pressure would be required to keep Trump in line. Recall what he told the Wall Street Journal, 10 days after Election Day, about how he expected Breitbart to cover the White House while he was working as Trump's chief strategist:

Mr. Bannon says he believes the site will “call it as it sees it” and that even the Trump administration will be open for criticism if it doesn’t “stay true to its vision.” He adds: “If we don’t, I assume they will hammer us.”

Bannon's remarks seemed like a signal to the team he was leaving behind at Breitbart: Hold Trump accountable for the things he promised.

In fact, that is what Bannon explicitly asked CPAC attendees to do in February. “Hold us accountable,” he said. “Hold us accountable to what we promised; hold us accountable for delivering on what we promised.”

Bannon appeared to sense early on that Trump could be pulled toward the political center by other, more moderate advisers. After he was fired on Friday, Bannon told the Weekly Standard that is exactly what has happened.

“The Trump presidency that we fought for, and won, is over,” he said. “We still have a huge movement, and we will make something of this Trump presidency. But that presidency is over.”

In Breitbart's recent coverage, we see Bannon's effort to salvage “something of this Trump presidency.” We see the carrot and the stick. Breitbart will, as Bannon said, “hammer” Trump when he breaks promises and shower him with praise when he follows through — or, at least, talks about following through. The goal is to compel Trump to govern more like he campaigned and to remind him that the support of his base, while strong, is not unconditional.