Terry Sullivan, who ran Senator Marco Rubioâs presidential campaign, said Mr. Trump and Breitbart âboth play to the lowest common denominator of peopleâs fears. Itâs a match made in heaven.â
Credit Damon Winter/The New York Times
For Mr. Trump, though, bringing in Mr. Bannon was the political equivalent of ordering comfort food. Only last week, Mr. Trump publicly expressed ambivalence about modifying his style. âI think I may do better the other way,â he told Time magazine. âThey would like to see it be a little bit different, a little more modified. I donât like to modify.â
Mr. Bannonâs transition from mischief-maker at Breitbart to the inner circle of the de facto leader of the Republican Party capped the second shake-up of Mr. Trumpâs campaign in two months.
Kellyanne Conway, a veteran pollster and strategist who was already advising Mr. Trump, will become his campaign manager and is expected to travel with the candidate, filling a void that opened up when Corey Lewandowski was fired on June 20.
Mr. Trumpâs loyalists put the best possible face on the changes announced Wednesday, but their timing, after a New York Times article detailing his advisersâ frustration at trying to impose discipline on him, underscored why so many in the party have soured on his prospects: His decisions are often made in reaction to news coverage.
Paul Manafort, the campaign chairman, will retain his title and focus on the political shop but was widely seen as being sidelined: Mr. Bannon and Ms. Conway have both developed close relationships with Mr. Trump, and Mr. Bannon is likely to be more amenable to letting him run the sort of media-focused campaign he prefers.
âThis is an exciting day for Team Trump,â Mr. Manafort wrote in an internal staff memo. âI remain the campaign chairman and chief strategist, providing the big-picture, long-range campaign vision,â he added.
On a conference call Wednesday morning, Jason Miller, a Trump spokesman, said the moves had been well received, along with a speech on crime reduction that he gave in Wisconsin, pointing to favorable coverage on the MSNBC show âMorning Joe.â
Under Mr. Bannon, Breitbart News has been an amen corner for Mr. Trump, and perhaps more relentless than any other conservative outlet in its criticism of the Republican establishment.
But what most distresses mainstream party strategists about the union of Mr. Trumpâs campaign with Breitbartâs guiding vision is the brand of populism that the website has advocated, and that Mr. Trump has championed.
Mr. Bannon has overseen a site that is focused primarily on pushing Republicans away from what it calls a globalist agenda and toward a hard-line and often overtly racial one, railing against what it sees as the threats of free trade, Hispanic migration and Islamist terrorism.
âThis is Trump going back to the nativism and nationalism that fueled his rise in the primary,â said Lanhee J. Chen, who was Mr. Romneyâs policy director in 2012. âBut itâs very dangerous to the future of the party because it only further narrows the appeal of a party whose appeal was already narrow going into this cycle.â
Mr. Chen called Mr. Trumpâs shift âa base reinforcement strategyâ and noted that it was very different from the tack of most party nominees, who use the final months of the presidential race to broaden their appeal in hopes of winning over the maximum number of voters.
But to those on the right who are hoping to permanently shift Republicans away from free-market conservatism and toward a harder-edged populism, the addition of Mr. Bannon was a victory for the âAmerica Firstâ approach they want to ingrain in the party.
âHe doesnât need any help formulating his message â his message is perfect,â the conservative author Ann Coulter said of Mr. Trump. Referring to Mr. Trumpâs policy adviser, speechwriter and warm-up speaker, she added, âMaybe he could use 10 more Stephen Millers.â
As comfortable as Mr. Trump may feel with Mr. Bannonâs style of politics, their unconventional alliance, and the possibility that the coming weeks could resemble a conservative publicity tour more than a conventional White House run, fueled speculation that Mr. Trump was already looking past November.
In recent months, Mr. Trump and his son-in-law, Jared Kushner, have quietly explored becoming involved with a media holding, either by investing in one or by taking one over, according to a person close to Mr. Trump who was briefed on those discussions.
At a minimum, the campaignâs homestretch offers Mr. Trump, who has begun to limit his national media appearances to conservative outlets, an opportunity to build his audience and steer his followers toward the combative Breitbart site. Even before announcing the staff shake-up, Mr. Trump intensified his criticism of the mainstream news media in a speech on Tuesday night in which he declared that he was running against the âmedia-donor-political complex.â
Mr. Trumpâs elevation of Mr. Bannon and Ms. Conway also highlights the growing influence of Robert Mercer and his daughter Rebekah, conservative donors from Long Island. The Mercers are investors in Breitbart, and their foundation funds a host of other conservative activist groups. They spent millions on Senator Ted Cruzâs behalf during the Republican primary, an effort Ms. Conway helped lead. And they began bankrolling a pro-Trump âsuper PACâ in recent weeks after becoming friendly with Mr. Trump, his daughter Ivanka and her husband, Mr. Kushner.
Credit Carlo Allegri/Reuters
At Breitbart and its sister foundation, the Government Accountability Institute, Mr. Bannon ran a hybrid between a news organization and an opposition-research operation aimed at discrediting Mrs. Clinton. The institute sponsored a book about Mrs. Clintonâs financial entanglements, âClinton Cash,â which spawned various articles in mainstream newspapers last year, including in The New York Times.
Rival conservative news organizations viewed Breitbart as something of an outlier, which was evident in the title of an article the Weekly Standard writer Stephen F. Hayes wrote on Wednesday: âTrump Has Decided to Live in Breitbartâs Alternative Reality.â
âItâs the merger of the Trump campaign with the kooky right,â William Kristol, editor of The Weekly Standard, said of Mr. Bannonâs new role.
Mr. Bannon has now joined with Mr. Ailes in a common cause on Mr. Trumpâs behalf, a mission that Breitbart never pretended to deny. But Mr. Ailesâs direct involvement casts a new light on how his network handled Mr. Trumpâs candidacy.
In the weeks before the Fox News host Gretchen Carlson filed the sexual harassment lawsuit that led to Mr. Ailesâs forced resignation, Mr. Ailes had been in regular contact with Mr. Trump and met with him at least twice, people briefed on the sessions said.
While meetings between a presidential candidate and the chairman of an influential television network are hardly unheard-of, especially with Mr. Trump, Mr. Ailesâs direct involvement in the campaign raises new questions about whether the sessions involved more than the usual complaints about coverage.
Before Mr. Ailesâs ouster, some of the networkâs journalists and contributors privately complained that Mr. Ailes was pushing them to be more supportive of Mr. Trump. This drew particular umbrage from longtime Republican staff members and contributors who either opposed Mr. Trumpâs candidacy on ideological grounds or believed it demanded tough reporting on journalistic grounds.
There was, though, one prominent conservative voice unambiguously in Mr. Ailesâs corner since the beginning of the sexual harassment scandal: Breitbart.
The website emerged as a singular defender of Mr. Ailes, with a piece about a planned walkout by network stars loyal to him should he be forced out â it never came to pass â and one by Mr. Bannon ridiculing the âminor Murdochsâ (the 21st Century Fox chief Rupert Murdochâs sons and co-executives, James and Lachlan), who were seen as leading the push for Mr. Ailes to resign.