A month after Republicans tried to unify in Cleveland, that effort appears to be canceled.

Because Donald Trump’s new campaign boss hates—really, really, really hates—the Republican establishment.

Stephen Bannon, who is the Trump campaign’s new chief executive, has spent the past few years as the chairman of Breitbart News and, more recently, the host of its daily morning radio show on SiriusXM.

He’s used his perch there to make the case that House Speaker Paul Ryan is a liberal globalist trying to sell out the American worker to foreign Islamist shills.

Under his tenure, Breitbart turned its guns on establishment Republicans like Senate Majority Leader Mitch McConnell and Sen. John McCain. Bannon himself took aim at former Republican House Speaker John Boehner, alleging he was involved in a “scheme” for political contributions.

“We don’t really believe there is a functional conservative party in this country, and we certainly don’t think the Republican Party is that,” he said at a National Press Club conference in 2013, in a video first noticed by The Wall Street Journal.

The campaign hire raises the question of whether Trump will wage a campaign against Hillary Clinton, given that he hired a campaign boss whose specialty is raging against other Republicans.

McConnell and McCain aren’t the only leading Republicans he loathes. Bannon prides himself on going after “The Establishment,” and veteran Washington hands share a similar animus toward him.

“Are Paul Ryan, Marco Rubio, and Reince Priebus fine with supporting a campaign run by Paul Manafort and Stephen Bannon?” Bill Kristol, the anti-Trump editor of the conservative Weekly Standard magazine, asked The Daily Beast.

Bannon’s pugilistic attitude toward many Republican insiders led Jason Johnson, a chief strategist for Ted Cruz’s presidential campaign, to speculate openly on Twitter about whether the hire didn’t mean Trump was declaring open war on Republican incumbents he had previously endorsed.

After months of stressing unity, Trump has apparently decided to “let Trump be Trump”—“I don’t want to pivot,” he said Tuesday—with all the fluctuating decision-making and Republican friendly fire that entails.

“All this shows is that he is somebody who is erratic, impulsive, thin-skinned, and responds to whatever pushback he is getting,” said Kendal Unruh, a Colorado Republican who led anti-Trump efforts as a delegate at the Republican convention.

With less than three months to go until Election Day, Trump has made a third change at the top of his campaign structure: swapping out political novice Corey Lewandowski for lobbyist Paul Manafort in hopes of calming nervous Republicans and getting the mogul’s message under control.

Now that’s over, and it appears going back to Trump’s original bombastic campaign style is again the plan. This return doesn’t exactly inspire the GOP faithful.

“The first wave of soldiers on D-Day had better odds of survival than a Trump senior staffer,” quipped John Noonan, a national-security expert who previously worked for Jeb Bush. “Trump is unaware, uncertain, unable, under attack, and underwater. Swapping out captains on a sinking ship isn’t going to do a damn thing.”

This latest captain doesn’t have a great winning record. Take his most recent crusade against GOP House Speaker Paul Ryan, who Trump would need to work with if elected. Over the past year, Bannon frequently hosted Ryan’s primary challenger, Paul Nehlen, on the show.

“He was raised in a petri dish there at the Heritage Institution,” Bannon sneered about Paul Ryan on the April 21 show.

Then he essentially endorsed Nehlen.

“He is the David to Paul Ryan’s Goliath out there in the first district in Wisconsin,” he said.

He referred to it as “a David versus Goliath campaign” again on June 27 when Nehlen came back on the program. But in this case, Goliath won. By 68 percentage points.

Ryan’s spokesman had no comment on Bannon’s hire.

Trump’s move will leave the Republican Party more divided than ever. RNC Chairman Reince Priebus—a loyal if bedraggled defender of Trump—is extremely close with Ryan, as both are from Wisconsin. An RNC spokesman did not respond to a request for comment.

Trump’s belated endorsement of Ryan and McCain—which he read off a TelePrompter just a few days before the primary—gave the impression that the party’s disparate factions might be, at long last, unifying.

But the fact that Trump’s campaign is now helmed by a man who built his reputation on attacking Republicans—and whom establishment Republicans loathe in turn—means those hopes of unity are probably toast.

—with additional reporting by Alexa Corse