In a major shakeup, The Wall Street Journal reports that Donald Trump has hired Stephen Bannon, executive chairman of Breitbart News, as chief executive of his campaign.

Breitbart, a far-right, hyper-conservative web publication, has been the leading voice of the online alternative right. The group has long held a favorable stance toward Gamergate, hiring notorious troll Milo Yiannopoulos to run a section of the site, and also takes a hardline, pro-Trump stance in election coverage.

That relationship has occasionally bubbled to the surface, as when a BuzzFeed report said Breitbart staff believed the publication was taking money from the Trump campaign (a charge Bannon denied). After an incident where former Trump campaign manager Corey Lewandowski grabbed Breitbart reporter Michelle Fields, the staff was instructed to not publicly talk about what happened. The site faced an internal rebellion over Trump coverage, which Bannon approved and orchestrated, according to a Vanity Fair report.

From his perch at Breitbart, Bannon himself has quietly built a reputation as a major GOP operator. An in-depth profile in Bloomberg Businessweek made the case that Bannon was the head of "the new vast right-wing conspiracy," using Breitbart to attack politicians like Hillary Clinton as well as more moderate conservative candidates, such as Jeb Bush. Bannon also founded a nonprofit, the Government Accountability Institute, dedicated to more thorough reporting. Bannon and Trump have known each other for years, the Journal points out.

The hire suggests Trump may again be looking to overhaul his campaign, which has struggled in recent polls. Paul Manafort, who was hired to run the campaign after Lewandowski's resignation, will remain campaign chairman, although the hiring of Bannon — along with the promotion of GOP strategist Kellyanne Conway to campaign manager — suggests Manafort will play a lesser role.

The Journal reports that Bannon will take a leave of absence from Breitbart to work on the campaign.