President-elect Donald J. Trump on Sunday chose Reince Priebus, the chairman of the Republican National Committee and a loyal campaign adviser, to be his White House chief of staff, turning to a Washington insider whose friendship with the House speaker, Paul D. Ryan, could help secure early legislative victories.
In selecting Mr. Priebus, the president-elect passed over Stephen K. Bannon, the right-wing media mogul who oversaw his presidential campaign. If Mr. Trump had appointed Mr. Bannon, a fierce critic of the Republican establishment, it would have signaled a continued disdain for a party that Mr. Trump fought throughout his campaign.
Mr. Trump’s choice is certain to anger some of his most conservative supporters, many of whom expect him to battle the Washington establishment over issues like taxes, immigration, trade, health care and the environment. They view Mr. Priebus as a deal maker who will be too eager to push the new president toward compromise.
In a statement Sunday afternoon, the transition team said Mr. Bannon would serve as the chief strategist and senior counselor in the White House. It emphasized that the two men would work “as equal partners to transform the federal government.”
Mr. Bannon — the longtime chairman of Breitbart News, a site known for its nationalist, racially charged, conspiracy-laden coverage — is likely to serve as a conduit to the populist right and conservative media outlets.
Breitbart News has accused President Obama of “importing more hating Muslims”; compared Planned Parenthood’s work to the Holocaust; called Bill Kristol, the conservative commentator, a “renegade Jew”; and advised female victims of online harassment to “just log off” and stop “screwing up the internet for men,” illustrating that point with a picture of a crying child.
The transition team appeared eager to ease concerns among Mr. Trump’s most fervent supporters over the selection of Mr. Priebus. To that end, the statement mentioned Mr. Bannon first.
“We had a very successful partnership on the campaign, one that led to victory,” Mr. Bannon said in the statement. “We will have that same partnership in working to help President-elect Trump achieve his agenda.”
Mr. Priebus said he looked forward to working with Mr. Bannon and Mr. Trump “to create an economy that works for everyone, secure our borders, repeal and replace Obamacare and destroy radical Islamic terrorism.”
The selection of Mr. Priebus to run the White House staff is partly a reflection of concern among Mr. Trump’s children, especially Ivanka Trump, as well as her husband, Jared Kushner, that the job should not be held by someone too controversial, according to several people familiar with the internal decision making.
But while Mr. Trump apparently feels comfortable with Mr. Priebus, the people with knowledge of the decision said that Mr. Bannon was better able to talk forcefully to the president-elect during difficult moments.
Mr. Priebus is expected to have multiple deputies, including Katie Walsh, the chief of staff of the Republican National Committee, who is close to Mr. Priebus and helped ensure a tight working relationship between the party’s operational infrastructure and Mr. Trump’s campaign.
Other advisers in Mr. Trump’s inner circle will also have his ear, including Mr. Kushner, who is likely to wield great influence over the new president regardless of whether he holds a formal title. Mr. Kushner, who has no experience in politics or government, is often the last person Mr. Trump turns to for counsel.
A onetime Goldman Sachs banker, Mr. Bannon has transformed himself into a media figure who favors a scorched-earth style of politics and views the corporate elite and the government establishment with disdain.
Breitbart News regularly traffics in racially charged accusations about Mr. Obama, provocative comparisons between abortion providers and Holocaust killers, and contempt for feminism. Many of its articles tap into a fierce populism not unlike the voter sentiment that helped fuel Mr. Trump’s victory.
Despite his image as a bomb-thrower, Mr. Bannon is also savvy at cutting deals to achieve his goals.
But as chief of staff, Mr. Priebus will be the one who has several hundred White House staff members reporting to him. He will be the primary gatekeeper for Mr. Trump and the person most responsible for steering the president’s agenda through Congress. That role will be especially critical for Mr. Trump, who has never served in government and has few connections to important political figures.
The selection of Mr. Priebus comes at the end of a roller-coaster year for the Republican Party, which saw Mr. Trump rewrite many of its policy orthodoxies, clash with its leaders in Congress and denigrate the Bush political dynasty.
As Mr. Trump denounced the Republican primary process as rigged and, on occasion, threatened to quit the party and run on his own, Mr. Priebus remained neutral. And when Mr. Trump secured the nomination, Mr. Priebus stood by his side.
Mr. Priebus worked with Mr. Trump on the nuts and bolts of presidential politics, trying to smooth his rough edges and staying in close contact as a bare-bones campaign prepared to go up against the Clinton machine.
On the surface, the two men could hardly be more different. While Mr. Trump, 70, is known for his brashness and at times his viciousness, the much younger Mr. Priebus, 44, is regarded for his low profile and humility.
A Wisconsin native and lawyer by training, Mr. Priebus has never held elected office. But he served as state treasurer and worked his way up through the Wisconsin Republican Party to become chairman, putting him on the Republican National Committee, where he eventually became general counsel to the chairman at the time, Michael Steele.
Now the longest-serving Republican National Committee chairman, Mr. Priebus was elected to the job in 2011, unseating Mr. Steele on the promise of modernizing the party and refilling its coffers. With his focus on fund-raising and fiscal issues, Mr. Priebus let Republican leaders in Congress be the voices of the party during the early part of his tenure. His profile rose as the 2016 election got into gear.
At times, Mr. Priebus, whose first name rhymes with “pints,” struggled to defend Mr. Trump’s antics, but he showed his loyalty by supplementing the campaign’s resources and by urging Republicans to fall in line behind the candidate in spite of their reservations.
When Mr. Trump emerged onstage to give his victory speech early Wednesday, Mr. Trump made his appreciation clear, dismissing rumors of tension with Mr. Priebus and singing his praises.
“I never had a bad second with him,” Mr. Trump said. “He’s an unbelievable star.”