Donald Trump’s campaign shake-up, featuring the addition of Steve Bannon, the head of Breitbart News, as CEO, is not being well received by political class Republicans on Capitol Hill.

As noted by The Hill, Bannon’s hard-right, pro-Trump website “has been synonymous with attacks on the GOP leadership.”

Bannon has taken a leave of absence as executive chairman of Breitbart News.

House Speaker Paul Ryan, who just received 85 percent of the vote in a contested primary, continues to be a consistent target of Breitbart News and Bannon himself, who has been very supportive of Ryan’s opponent in the Wisconsin district. Senate Majority Leader Mitch McConnell has also drawn fire.

More from The Hill:

More recently, as Ryan faced a primary challenge, Breitbart pounded out a drumbeat of negative stories. Among the headlines: “Paul Ryan plummets to 43 percent in new primary poll”; “Paul Ryan running scared in final days ahead of primary election”; “Desperate Paul Ryan floods Wisconsin with misleading television ads.”

According to the online news source, the appointment of the “street fighter” Bannon to head up Trump’s campaign has Republicans “apoplectic,” to include some who have endorsed the real estate tycoon.

“Breitbart has no credibility outside of the most extreme conservative wing of our party,” one lawmaker told The Hill. “Frankly, the same could be said of Kellyanne Conway.”

Conway was named Trump’s campaign manager.

“This would seem to signal that Trump is ready to go double-barrel against all of Washington, Republicans and Democrats alike,” the unidentified House member said. “Breitbart takes a flamethrower to Washington and plays very loose with the facts. I would anticipate an even more bellicose, even less-connected-to-the-facts approach from the Trump campaign moving forward.”

John Feehery, a GOP strategist and columnist for The Hill, disagreed with the assessment of Conway as campaign manager, which he described as “a good hire,” but there was no love lost for Bannon.

“I know how it is going to be perceived on the Hill and among the leadership: it’s not gonna be perceived very well,” Feehery predicted. “Because Breitbart are nuts! They’re unhinged. They do stories that are not journalistically credible.”

A second Republican member of the House agreed.

“This doesn’t sound to me like someone interested in running a rational, positive message, let alone winning,” the lawmaker told The Hill. “Breitbart isn’t a legitimate news organization. It’s a disgraceful propaganda machine that is trying to divide the party.”

And if this isn’t convincing enough that the political class has chills running down its spine, here are a few tweets from Robert Costas, a political reporter at the pro-establishment Washington Post, describing Wednesday’s shake up:

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Bannon's Breitbart, in both substance and style, was an incubator for Trumpism https://t.co/y1QSTGBfU9 — Robert Costa (@costareports) August 18, 2016